Methods to reduce the inflammatory response critical in the pathogenesis of asthma and asthma exacerbations via the introduction of autologous pla2g5-deficient suppressive macrophages into the airways of patients with asthma.
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1. A method of reducing pulmonary inflammation in a subject, the method comprising:
identifying a subject as having an allergen-induced asthma; and
delivering a population of pla2g5-deficient suppressive macrophages to the subject identified as having an allergen-induced asthma, preferably to a lung or airway of the subject.
11. A method of preparing a population of pla2g5-deficient suppressive macrophages, the method comprising:
obtaining a sample comprising peripheral blood from a subject;
enriching the sample for mononuclear cells;
maintaining the mononuclear cells under conditions to promote differentiation of the mononuclear cells into a population of macrophages, wherein the cells are maintained in the presence of Granulocyte macrophage colony-stimulating factor (GM-CSF), preferably for 13 days;
contacting the population of macrophages with an inhibitory nucleic acid that reduces expression of pla2g5; and
polarizing the cells with interleukin 4 (IL-4),
thereby preparing a population of pla2g5-deficient suppressive macrophages.
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20. A method of reducing allergen-induced pulmonary inflammation in a subject, the method comprising administering the population of pla2g5-deficient suppressive macrophages of
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This application is a § 371 National Stage Application of PCT/US2017/020479, filed Mar. 2, 2017, which claims the benefit of U.S. Provisional Application Ser. No. 62/302,251, filed on Mar. 2, 2016; 62/314,136, filed on Mar. 28, 2016; and 62/393,244, filed on Sep. 12, 2016. The entire contents of the foregoing are incorporated herein by reference.
This invention was made with Government support under Grant No. R01HL113071 awarded by the National Institutes of Health. The Government has certain rights in the invention.
Described herein are methods to reduce the inflammatory response critical in the pathogenesis of asthma and asthma exacerbations via the introduction of autologous Pla2g5-deficient suppressive macrophages into the airways of patients with asthma.
Asthma is a heterogeneous chronic disease characterized by persistent pulmonary inflammation, episodic bronchoconstriction, and airway remodeling. Alternaria Alternata is a common fungus that is a source of allergens associated with the development of asthma and asthma exacerbations. In mice, Alternaria allergens trigger accumulation of eosinophils and the development of airway hyperreactivity1, 2, each of which prominently involves effectors of the innate immune system1, 3, 4. Acute exposure of the airways of naïve mice to Alternaria causes the rapid release of IL-33 by epithelial cells, followed by the activation of group 2 innate lymphoid cells (ILC2)3, 5. Longer term repetitive administration of Alternaria upregulates lung expression of IL-33, and promotes incremental ILC2-dependent lung eosinophilic inflammation1. ILC2s lack cell surface markers associated with major hematopoietic lineages (Lin)6-8. In the lung they express Thy1.2 (CD45+ Lin− Thy1.2+)9 and activation molecules including ST2 (IL1R1), Sca-1, CD278 (ICOS), CD25 (IL-2Rα), CD127 (IL-7Rα), CD117 (c-Kit), and IL-17RB (IL-25R)1, 10-12. Following activation, ILC2s produce IL-5 and IL-13 (as well as other cytokines), which mediate pulmonary eosinophilia, airway hyperreactivity1, 12, 13 and macrophage activation14. Although IL-33 in naïve mouse lung is principally derived from structural cells15, hematopoietic cell (including macrophages) can express IL-33 inducibly16, 17. Macrophages can activate ILC2 through an IL-33-dependent mechanism in a model of influenza-induced airway hyperreactivity10.
As described herein, the role of Pla2g5-expressing macrophages in activation of ILC2, IL-33 responsive cells, which were recently identified as key mediators in the pathogenesis of asthma and asthma exacerbations. In a mouse model of asthma induced by the fungus Alternaria alternata (characterized by increased numbers of eosinophils and ILC2 activation), mice lacking Pla2g5 had markedly reduced lung ILC2 activation and eosinophilia (
However, the transfer of Wt BM-macrophages into Pla2g5-null mice did not restore inflammation in Pla2g5-null mice to exactly the same levels of Wt mice (
Thus, provided herein are methods for reducing pulmonary inflammation in a subject, e.g., a mammalian subject, preferably a human subject. The methods include delivering a population of cells comprising Pla2g5-deficient suppressive macrophages (preferably a population comprising at least 80% Pla2g5-deficient suppressive macrophages, e.g., at least 85%, 90%, 95%, or 99% pure Pla2g5-deficient suppressive macrophages) to a subject in need thereof, preferably to a lung or airway of the subject. In some embodiments, the methods include administering at least 0.5 million, 1 million, 2 million, or 4 million, or more, e.g., 0.25 to 5 million cells.
Also provided herein is a population of Pla2g5-deficient suppressive macrophages, at least 80% Pla2g5-deficient suppressive macrophages, e.g., at least 85%, 90%, 95%, or 99% pure Pla2g5-deficient suppressive macrophages, e.g., at least 0.5 million, 1 million, 2 million, or 4 million, or more, e.g., 0.25 to 5 million cells, for use in a method of reducing pulmonary inflammation in a subject, preferably wherein the macrophages are formulated for delivery to a lung or airway of a subject in need thereof.
In some embodiments, the population of Pla2g5-deficient suppressive macrophages is autologous to the subject.
In some embodiments, the population of Pla2g5-deficient suppressive macrophages comprises an inhibitory nucleic acid that specifically reduces expression of Pla2g5.
In some embodiments, the inhibitory nucleic acid is an antisense oligonucleotide, siRNA, shRNA, or CRISPR/Cas9 guide RNA.
In some embodiments, the inhibitory nucleic acid is modified, e.g., comprises a modified backbone or at least one modified nucleotide. In some embodiments, the inhibitory nucleic acid comprises at least one locked nucleic acid.
In some embodiments, the inhibitory nucleic acid is a gapmer or mixmer.
In some embodiments, the subject has asthma.
Also provided herein are methods for preparing a population of Pla2g5-deficient suppressive macrophages. The methods include obtaining a sample comprising peripheral blood from a subject (e.g., a subject who has pulmonary inflammation, e.g., asthma, and is in need of treatment using a method described herein); enriching the sample for mononuclear cells (CD14+ monocytes); and maintaining the mononuclear cells under conditions sufficient to promote differentiation of the mononuclear cells into a population of macrophages (CD64+ macrophages), e.g., culturing the cells for 7-14 days, e.g., 13 days, in culture medium containing the growth factor Granulocyte macrophage colony-stimulating factor (GMCSF) or MCSF; contacting the population of macrophages with an inhibitory nucleic acid that specifically reduces expression of Pla2g5, e.g., for about 24 hours; and activating the macrophages using IL-4 to express M2 markers (CCL22, TGM2), e.g., for about 6-48 hours, thereby preparing a population of Pla2g5-deficient suppressive macrophages (which have reduced expression of PLA2G5, and optionally also reduced expression of CCL22 and TGM2).
In some embodiments, the inhibitory nucleic acid is an antisense oligonucleotide, siRNA, shRNA, or CRISPR/Cas9 guide RNA.
In some embodiments, the inhibitory nucleic acid is modified, e.g., comprises a modified backbone or at least one modified nucleotide. In some embodiments, the inhibitory nucleic acid comprises at least one locked nucleic acid.
Also provided herein are populations of Pla2g5-deficient suppressive macrophages prepared by a method described herein, as well as methods of reducing pulmonary inflammation in a subject, comprising administering the population of Pla2g5-deficient suppressive macrophages to a subject in need thereof.
In some embodiments of the methods described herein, the cells are delivered by an aerosol spray of a suspension of cells into a nasal passage of the subject; by intratracheal or intrabracheal distillation; or by intravenous administration.
As used herein, the term “about” means plus or minus 10%.
Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Methods and materials are described herein for use in the present invention; other, suitable methods and materials known in the art can also be used. The materials, methods, and examples are illustrative only and not intended to be limiting. All publications, patent applications, patents, sequences, database entries, and other references mentioned herein are incorporated by reference in their entirety. In case of conflict, the present specification, including definitions, will control.
Other features and advantages of the invention will be apparent from the following detailed description and figures, and from the claims.
Phospholipases A2 (PLA2) are a family of enzymes that release lysophospholipids and free fatty acids (FFAs) from membrane glycerophospholipids18, 19. While FFAs such as arachidonic acid (AA) can be converted to receptor-active eicosanoids (including prostaglandins and leukotrienes), other FFAs can act directly at cognate receptors to regulate metabolic processes and inflammatory responses20. PLA2s may have substrate preferences and specific cell and tissue expression, therefore serving context-specific functions. Group V PLA2 (Pla2g5) preferentially releases lysophosphatidylcholine (LPC) and the FFAs linoleic acid (LA) and oleic acid (OA)21-23, and is prevalently expressed by innate immune cells, including dendritic cells and macrophages24-26, as well as epithelial cells25, 27. Using a mouse model of allergic lung inflammation induced by the allergens of house dust mite Dermatophagoides harac, the present inventors demonstrated that Pla2g5 was necessary for the effector functions of both dendritic cells and macrophages24, 25. Adoptive transfer studies showed that Pla2g5 expression by macrophages was required for their generation of CCL22 and recruitment of T cells into the lungs25.
As demonstrated herein, ILC2 activation is impaired in Pla2g5-null mice exposed to Alternaria. However adoptive transfers of macrophages restored ILC2 activation by a mechanism that is at least in part dependent on Pla2g5-dependent production of IL-33, LA and OA, which sustain ILC2 activation in vitro and in vivo, and on Pla2g5-dependent expression of the LA-preferring FFA receptor-1 (FFAR1) by ILC2s.
It is now well established that ILC2 are key effectors of pulmonary inflammation. Their contribution is particularly evident in models triggered by the release of alarmins (IL-33, IL-25, TSLP) from epithelial cells2, 4, 9, 11, 38, 39 in response to environmental proteases11, many of which are relevant to asthma in humans13. IL-33, alone and in combination with IL-25, TSLP, and other cytokines can directly induce IL-5, IL-13, and IL-9 generation from ILC2s, promoting eosinophilic inflammation and goblet cell metaplasia that can occur independently of or in concert with adaptive immunity. The Alternaria model of pulmonary inflammation has been particularly useful to establish the contribution of innate, epithelial-derived alarmins and their downstream effects on ILC2 activation and subsequent development of airway inflammation1, 3. While macrophages can also express IL-3340, and other innate cell types have been proposed to interact with ILC241, no previous studies had established whether macrophages can activate ILC2 in Alternaria-induced pulmonary inflammation and which mediators might be involved. Pla2g5-null mice show markedly impaired type 2 pulmonary inflammation that reflects, at least in part, a requirement for cell-intrinsic Pla2g5 for macrophage effector functions25, 26. We therefore investigated the role of Pla2g5 in general and macrophage-associated Pla2g5 in particular, in lipid-generating function and its potential downstream effects on ILC2 activation in a model of pulmonary inflammation induced by Alternaria.
Wt and Pla2g5-null mice were subjected to a protocol involving the administration of Alternaria four times over a 10-day period, which elicits prominent contributions from IL-33 and ILC2s. The marked pulmonary eosinophilia and increases in the numbers of total and activated ILC2s observed in Wt mice (
When administered exogenously to I Wt mice, r-IL-33 is sufficient alone to drive a robust type 2 inflammatory response that depends on ILC23, 38. Despite the evident role of Pla2g5 in IL-33 induction by macrophages, the direct administration of IL-33 to I Pla2g5-null mice was insufficient to induce inflammation, ILC2 expansion, and macrophage activation (
Our data clearly identify a role for macrophages, and Pla2g5-derived FFAs, as activators of ILC2, acting in concert with IL-33. It is likely that the coordinate action of ILC2, macrophages and epithelial cells induces pulmonary inflammation, highlighting a complex interplay of innate cells in the lung4, 12, 44. These data also suggest that FFAs directly activate ILC2 through FFAR1 expressed on ILC2 in a Pla2g5-dependent fashion. Thus, our observations suggest that macrophage-derived FFAs amplify innate, IL-33-triggered type 2 immunopathology in diseases such as asthma. We speculate that LA, derived at least in part from Pla2g5-expressing macrophages, may contribute to the function of ILC2s in other circumstances, such as homeostasis of adipose tissue and glucose metabolism where macrophages, Pla2g5, IL-33, and ILC2 have all been implicated22, 45.
Methods of Treatment
The methods described herein include methods for the treatment of disorders associated with inflammation, e.g., pulmonary inflammation. In some embodiments, the disorder is asthma. Generally, the methods include administering a therapeutically effective amount of autologous macrophages lacking Pla2g5 as described herein, to a subject who is in need of, or who has been determined to be in need of, such treatment. In some embodiments, the methods include administering at least 0.5 million, 1 million, 2 million, or 4 million, or more, e.g., 0.25 to 5 million cells.
As used in this context, to “treat” means to ameliorate at least one symptom of the disorder associated with pulmonary inflammation. Often, pulmonary inflammation results in breathlessness, wheezing and a variable airflow obstruction; thus, a treatment can result in a reduction in breathlessness, wheezing and a variable airflow obstruction and a return or approach to normal breathing. Administration of a therapeutically effective amount of a treatment described herein will result in decreased levels of pulmonary inflammation.
Asthma
A variety of cellular inflammatory phenotypes is associated with asthma, and airway hyper-responsiveness (AHR), an increase in responsiveness of the conducting airways, is characteristic. Symptoms include breathlessness, wheezing and a variable airflow obstruction. A diagnosis of asthma can be made by a healthcare provider using standard diagnostic methods, e.g., following the Guidelines for the Diagnosis and Management of Asthma (EPR-3) (2007), including a subject history of coughing, recurrent wheezing, recurrent difficulty breathing, and recurrent chest tightness, that may occur or worsen at night or with exercise, viral infection, exposure to allergens and irritants, changes in weather, hard laughing or crying, stress, or other factors. Spirometry or imaging methods can be used to determine that airway obstruction is at least partially reversible. See, e.g., Murdoch and Lloyd, Mutat Res. 2010 Aug. 7; 690(1-2): 24-39.
Pla2g5-Deficient Suppressive Macrophages
The present methods include the administration of Pla2g5-deficient suppressive macrophages, preferably autologous macrophages. As used herein, the term “Pla2g5-deficient suppressive macrophages” refers to macrophages in which Pla2g5 expression levels have been artificially decreased by at least 70%, to no more than 30% of normal levels, or decreased by at least 75%, 80%, 90%, or 95% or more. The methods can include obtaining peripheral blood from a subject with asthma (i.e., a subject to be treated using a method described herein), and isolating monocytes from the sample to provide an enriched sample of monocytes (CD14+). In some embodiments, magnetic activated cell sorting (MACS), e.g., positive or negative selection, is used, e.g., with a commercially available kit (Monocyte Isolation Kit II, human, Miltenyi Biotec), wherein non-monocyte cells are indirectly magnetically labeled using a cocktail of biotin-conjugated antibodies as well as anti-biotin beads; highly enriched unlabeled monocytes are obtained by depletion of the magnetically labeled cells. Other methods can also be used, e.g., percoll gradients (de Almeida e al., Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol. 95(2): 221-223, March/April 2000); positive selection of monocytes by anti-CD14-coated microbeads (Elkord et al., Immunology. 2005 February; 114(2): 204-212; Monocyte Isolate Kit with CD14 MicroBeads, Miltenyi biotec); plate-adherence isolation (Elkord et al., Immunology. 2005 February; 114(2): 204-212, Freundlich and Avdalovic. 1983. J. Immunol. Methods 62: 31-37); double density gradient centrifugation (Menck et al., J. Vis. Exp. (91), e51554, doi:10.3791/51554 (2014)); or RosetteSep antibody cocktail (this antibody cocktail crosslinks unwanted cells to red blood cells (RBCs), forming rosettes. The unwanted cells then pellet with the free RBCs when centrifuged over a density centrifugation medium (e.g., Ficoll-Paque™ PLUS, Lymphoprep™; Stemcell Technologies, France). Ficoll-Paque PLUS is a sterile, ready to use density gradient medium for purifying lymphocytes in high yield and purity from small or large volumes of human peripheral blood, using a simple and rapid centrifugation procedure based on the method developed by Bøyum et al., Scand J Clin Lab Invest 21 Suppl, 97, 77-89 (1968). It is an aqueous solution of density 1.077+0.001 g/ml containing 5.7 g Ficoll 400 and 9 g sodium diatrizoate with 0.0231 g calcium disodium ethylenediamintetraacetic acid in every 100 ml. Ficoll 400 is a synthetic high molecular weight (Mw 400 000) polymer of sucrose and epichlorohydrin that is readily soluble in water. Ficoll 400 molecules are highly branched, approximately spherical, and compactly coiled with a Stokes' radius of approximately 10 nm.
The monocytes are then derived into macrophages, e.g., using a suitable protocol, a number of which are known in the art. See, e.g., below and Yamaguchi et al., J L B 2016; Menck et al., J. Vis. Exp. (91), e51554 (2014); Ohradanova-Repic et al., Clinical & Translational Immunology (2016) 5, e55; Mia et al., Scand J Immunol. 2014 May; 79(5):305-14). In preferred embodiments, the methods include incubating the cells in the presence of recombinant human GM-CSF for 7-14 or 12-14 days, preferably 13 days, which induces expression of the generic macrophage marker CD64. Alternatively, macrophage colony-stimulating factor (M-CSF) for about 7 days can be used (see Ohta et al., Journal of immunology 2013; 190(12): 5927-5938).
Then, the macrophages are converted into suppressive macrophages by reducing the expression of Pla2g5 using an inhibitory nucleic acid to knock down the protein, e.g., using siRNA, shRNA, antisense, or CRISPR/Cas9 targeting Pla2g5. The cells are maintained in media comprising the inhibitory nucleic acid for about 12-36 hours, e.g., about 24 hours, preferably followed by 24 hours in GM-CSF-containing medium.
This is followed by treatment with IL-4, e.g., for 6-48 hours or so, for M2 activation; expression of CCL2 and TGM2 is increased in the M2 cells after IL-4 treatment. In the Pla2g5 knock-out macrophages, CCL22 and TGM2 expression is also reduced as compared to wild type cells exposed to the same protocol. Note that Pla2g5 and TGM2 are enzymes and the enzymatic activity is reduced for both enzymes after knocking down Pla2g5. These differences could be explained by the transient removal of Pla2g5 in human cells.
The cells can optionally be purified as needed to provide a population comprising at least 80% Pla2g5-deficient suppressive macrophages, e.g., at least 85%, 90%, 95%, or 99% pure Pla2g5-deficient suppressive macrophages, and/or allowed to proliferate, to provide at least 0.5 million, 1 million, 2 million, or 4 million, or more, e.g., 0.25 to 5 million cells.
The final step would be to re-introduce Pla2g5-null macrophages into the airways of patients with asthma to obtain suppression/reduction of inflammation and therefore asthma, as demonstrated by the in vivo mouse experiments (
Pla2g5 Inhibitory Nucleic Acids
Inhibitory nucleic acids useful in the present methods and compositions include CRISPR guide RNAs (used in conjunction with a CRISPR/Cas9 protein) antisense oligonucleotides, single- or double-stranded RNA interference (RNAi) compounds such as siRNA or shRNA compounds, compounds with modified bases such as locked nucleic acids (LNAs), peptide nucleic acids (PNAs), ribozymes, gapmers, mixmers, and other oligomeric compounds or oligonucleotide mimetics that hybridize to at least a portion of the target Pla2g5 nucleic acid and modulate its function to reduce expression of Pla2g5 protein. Reference sequences for human Pla2g5 can be found in GenBank at NM 000929.2 (nucleic acid) and NP 000920.1 (protein).
In some embodiments, the inhibitory nucleic acids are 10 to 50, 13 to 50, or 13 to 30 nucleotides in length. One having ordinary skill in the art will appreciate that this embodies oligonucleotides having antisense portions of 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, or 50 nucleotides in length, or any range there within. In some embodiments, the oligonucleotides are 15 nucleotides in length. In some embodiments, the antisense or oligonucleotide compounds of the invention are 12 or 13 to 30 nucleotides in length. One having ordinary skill in the art will appreciate that this embodies inhibitory nucleic acids having antisense portions of 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29 or 30 nucleotides in length, or any range there within. Suitable sequences can be identified, e.g., using computational and/or “gene walk” methods. To design and to optimize the inhibitory activity of the inhibitory nucleic acids; for example, a series of oligonucleotides of 10-30 nucleotides spanning the length of a target nucleic acid can be prepared, followed by testing for activity. Optionally, gaps, e.g., of 5-10 nucleotides or more, can be left between the inhibitory nucleic acids to reduce the number of oligonucleotides synthesized and tested. GC content is preferably between about 30 60%.
In some embodiments, the inhibitory nucleic acids are chimeric oligonucleotides that contain two or more chemically distinct regions, each made up of at least one nucleotide. These oligonucleotides typically contain at least one region of modified nucleotides that confers one or more beneficial properties (such as, for example, increased nuclease resistance, increased uptake into cells, increased binding affinity for the target) and a region that is a substrate for enzymes capable of cleaving RNA:DNA, LNA:DNA or RNA:RNA hybrids. Chimeric inhibitory nucleic acids of the invention may be formed as composite structures of two or more oligonucleotides, modified oligonucleotides, oligonucleosides and/or oligonucleotide mimetics as described above. Such compounds have also been referred to in the art as hybrids or gapmers (chimeric antisense oligonucleotide that contains a central block of deoxynucleotide monomers sufficiently long to induce Rnase H cleavage), as well as mixmers (oligomers comprising alternating short stretches of LNA and DNA). Representative United States patents that teach the preparation of such hybrid structures comprise, but are not limited to, U.S. Pat. Nos. 5,013,830; 5,149,797; 5,220,007; 5,256,775; 5,366,878; 5,403,711; 5,491,133; 5,565,350; 5,623,065; 5,652,355; 5,652,356; 5,700,922; 8,604,192; 8,697,663; 8,703,728; 8,796,437; 8,865,677; and 8,883,752 each of which is herein incorporated by reference.
In some embodiments, the inhibitory nucleic acid comprises at least one nucleotide modified at the 2′ position of the sugar, most preferably a 2′-O-alkyl, 2′-O-alkyl-O-alkyl or 2′-fluoro-modified nucleotide. In other preferred embodiments, RNA modifications include 2′-fluoro, 2′-amino and 2′ O-methyl modifications on the ribose of pyrimidines, abasic residues or an inverted base at the 3′ end of the RNA. Such modifications are routinely incorporated into oligonucleotides and these oligonucleotides have been shown to have a higher Tm (i.e., higher target binding affinity) than; 2′-deoxyoligonucleotides against a given target.
A number of nucleotide and nucleoside modifications have been shown to make the oligonucleotide into which they are incorporated more resistant to nuclease digestion than the native oligodeoxynucleotide; these modified oligos survive intact for a longer time than unmodified oligonucleotides. Specific examples of modified oligonucleotides include those comprising modified backbones, for example, phosphorothioates, phosphotriesters, methyl phosphonates, short chain alkyl or cycloalkyl intersugar linkages or short chain heteroatomic or heterocyclic intersugar linkages. Most preferred are oligonucleotides with phosphorothioate backbones and those with heteroatom backbones, particularly CH2-NH—O—CH2, CH, ˜N(CH3)˜O˜CH2 (known as a methylene(methylimino) or MMI backbone], CH2-O—N(CH3)-CH2, CH2-N(CH3)-N(CH3)-CH2 and O—N(CH3)-CH2-CH2 backbones, wherein the native phosphodiester backbone is represented as O—P—O—CH,); amide backbones (De Mesmaeker (1995) Ace. Chem. Res. 28:366-374); morpholino backbone structures (Summerton and Weller, U.S. Pat. No. 5,034,506); peptide nucleic acid (PNA) backbone (wherein the phosphodiester backbone of the oligonucleotide is replaced with a polyamide backbone, the nucleotides being bound directly or indirectly to the aza nitrogen atoms of the polyamide backbone, Nielsen (1991) Science 254, 1497). Phosphorus-containing linkages include, but are not limited to, phosphorothioates, chiral phosphorothioates, phosphorodithioates, phosphotriesters, aminoalkylphosphotriesters, methyl and other alkyl phosphonates comprising 3′alkylene phosphonates and chiral phosphonates, phosphinates, phosphoramidates comprising 3′-amino phosphoramidate and aminoalkylphosphoramidates, phosphonoacetate phosphoramidates, thionophosphoramidates, thionoalkylphosphonates, thionoalkylphosphotriesters, and boranophosphates having normal 3′-5′ linkages, 2′-5′ linked analogs of these, and those having inverted polarity wherein the adjacent pairs of nucleoside units are linked 3′-5′ to 5′-3′ or 2′-5′ to 5′-2′; see U.S. Pat. Nos. 3,687,808; 4,469,863; 4,476,301; 5,023,243; 5,177,196; 5,188,897; 5,264,423; 5,276,019; 5,278,302; 5,286,717; 5,321,131; 5,399,676; 5,405,939; 5,453,496; 5,455,233; 5,466,677; 5,476,925; 5,519,126; 5,536,821; 5,541,306; 5,550,111; 5,563,253; 5,571,799; 5,587,361; and 5,625,050.
Morpholino-based oligomeric compounds are described in Dwaine A. Braasch and David R. Corey (2002) Biochemistry 41(14), 4503-4510); Genesis, volume 30, issue 3, 2001; Heasman, (2002) Dev. Biol. 243, 209-214; Nasevicius (2000) Nat. Genet. 26, 216-220; Lacerra (2000) Proc. Natl. Acad. Sci. 97, 9591-9596; and U.S. Pat. No. 5,034,506, issued Jul. 23, 1991. Cyclohexenyl nucleic acid oligonucleotide mimetics are described in Wang (2000) Am. Chem. Soc. 122, 8595-8602.
Modified oligonucleotide backbones that do not include a phosphorus atom therein have backbones that are formed by short chain alkyl or cycloalkyl internucleoside linkages, mixed heteroatom and alkyl or cycloalkyl internucleoside linkages, or one or more short chain heteroatomic or heterocyclic internucleoside linkages. These comprise those having morpholino linkages (formed in part from the sugar portion of a nucleoside); siloxane backbones; sulfide, sulfoxide and sulfone backbones; formacetyl and thioformacetyl backbones; methylene formacetyl and thioformacetyl backbones; alkene containing backbones; sulfamate backbones; methyleneimino and methylenehydrazino backbones; sulfonate and sulfonamide backbones; amide backbones; and others having mixed N, O, S and CH2 component parts; see U.S. Pat. Nos. 5,034,506; 5,166,315; 5,185,444; 5,214,134; 5,216,141; 5,235,033; 5,264,562; 5,264,564; 5,405,938; 5,434,257; 5,466,677; 5,470,967; 5,489,677; 5,541,307; 5,561,225; 5,596,086; 5,602,240; 5,610,289; 5,602,240; 5,608,046; 5,610,289; 5,618,704; 5,623,070; 5,663,312; 5,633,360; 5,677,437; 5,677,439; and 8,927,513 each of which is herein incorporated by reference.
One or more substituted sugar moieties can also be included, e.g., one of the following at the 2′ position: OH, SH, SCH3, F, OCN, OCH3, OCH3O(CH2)nCH3, O(CH2)nNH2 or O(CH2)nCH3 where n is from 1 to about 10; Ci to C10 lower alkyl, alkoxyalkoxy, substituted lower alkyl, alkaryl or aralkyl; Cl; Br; CN; CF3; OCF3; O-, S-, or N-alkyl; O-, S-, or N-alkenyl; SOCH3; SO2CH3; ONO2; NO2; N3; NH2; heterocycloalkyl; heterocycloalkaryl; aminoalkylamino; polyalkylamino; substituted silyl; an RNA cleaving group; a reporter group; an intercalator; a group for improving the pharmacokinetic properties of an oligonucleotide; or a group for improving the haracterization properties of an oligonucleotide and other substituents having similar properties. A preferred modification includes 2′-methoxyethoxy [2′-0-CH2CH2OCH3, also known as 2′-O-(2-methoxyethyl)] (Martin (1995) Helv. Chim. Acta 78, 486). Other preferred modifications include 2′-methoxy (2′-0-CH3), 2′-propoxy (2′-OCH2CH2CH3) and 2′-fluoro (2′-F). Similar modifications may also be made at other positions on the oligonucleotide, particularly the 3′ position of the sugar on the 3′ terminal nucleotide and the 5′ position of 5′ terminal nucleotide. Oligonucleotides may also have sugar mimetics such as cyclobutyls in place of the pentofuranosyl group.
Inhibitory nucleic acids can also include, additionally or alternatively, nucleobase (often referred to in the art simply as “base”) modifications or substitutions. As used herein, “unmodified” or “natural” nucleobases include adenine (A), guanine (G), thymine (T), cytosine (C) and uracil (U). Modified nucleobases include nucleobases found only infrequently or transiently in natural nucleic acids, e.g., hypoxanthine, 6-methyladenine, 5-Me pyrimidines, particularly 5-methylcytosine (also referred to as 5-methyl-2′ deoxycytosine and often referred to in the art as 5-Me-C), 5-hydroxymethylcytosine (HMC), glycosyl HMC and gentobiosyl HMC, as well as synthetic nucleobases, e.g., 2-aminoadenine, 2-(methylamino)adenine, 2-(imidazolylalkyl)adenine, 2-(aminoalklyamino)adenine or other heterosubstituted alkyladenines, 2-thiouracil, 2-thiothymine, 5-bromouracil, 5-hydroxymethyluracil, 8-azaguanine, 7-deazaguanine, N6 (6-aminohexyl)adenine, 2,6-diaminopurine; 5-ribosyluracil (Carlile (2014) Nature 515(7525): 143-6). Kornberg, A., DNA Replication, W. H. Freeman & Co., San Francisco, 1980, pp 75-77; Gebeyehu (1987) Nucl. Acids Res. 15:4513). A “universal” base known in the art, e.g., inosine, can also be included. 5-Me-C substitutions have been shown to increase nucleic acid duplex stability by 0.6-1.2<0>C. (Sanghvi, Y. S., in Crooke, S. T. and Lebleu, B., eds., Antisense Research and Applications, CRC Press, Boca Raton, 1993, pp. 276-278) and are presently preferred base substitutions.
It is not necessary for all positions in a given oligonucleotide to be uniformly modified, and in fact more than one of the aforementioned modifications may be incorporated in a single oligonucleotide or even at within a single nucleoside within an oligonucleotide. In some embodiments, both the nucleobase and backbone may be modified to enhance stability and activity (El-Sagheer (2014) Chem Sci 5:253-259).
In some embodiments, both a sugar and an internucleoside linkage, i.e., the backbone, of the nucleotide units are replaced with novel groups. The base units are maintained for hybridization with an appropriate nucleic acid target compound. One such oligomeric compound, an oligonucleotide mimetic that has been shown to have excellent hybridization properties, is referred to as a peptide nucleic acid (PNA). In PNA compounds, the sugar-backbone of an oligonucleotide is replaced with an amide containing backbone, for example, an aminoethylglycine backbone. The nucleobases are retained and are bound directly or indirectly to aza nitrogen atoms of the amide portion of the backbone. Representative United States patents that teach the preparation of PNA compounds comprise, but are not limited to, U.S. Pat. Nos. 5,539,082; 5,714,331; and 5,719,262, each of which is herein incorporated by reference. Further teaching of PNA compounds can be found in Nielsen (1991) Science 254, 1497-1500; and Shi (2015).
Inhibitory nucleic acids can also include one or more nucleobase (often referred to in the art simply as “base”) modifications or substitutions. As used herein, “unmodified” or “natural” nucleobases comprise the purine bases adenine (A) and guanine (G), and the pyrimidine bases thymine (T), cytosine (C) and uracil (U). Modified nucleobases comprise other synthetic and natural nucleobases such as 5-methylcytosine (5-me-C), 5-hydroxymethyl cytosine, xanthine, hypoxanthine, 2-aminoadenine, 6-methyl and other alkyl derivatives of adenine and guanine, 2-propyl and other alkyl derivatives of adenine and guanine, 2-thiouracil, 2-thiothymine and 2-thiocytosine, 5-halouracil and cytosine, 5-propynyl uracil and cytosine, 6-azo uracil, cytosine and thymine, 5-uracil (pseudo-uracil), 4-thiouracil, 8-halo, 8-amino, 8-thiol, 8-thioalkyl, 8-hydroxyl and other 8-substituted adenines and guanines, 5-halo particularly 5-bromo, 5-trifluoromethyl and other 5-substituted uracils and cytosines, 7-methylquanine and 7-methyladenine, 8-azaguanine and 8-azaadenine, 7-deazaguanine and 7-deazaadenine and 3-deazaguanine and 3-deazaadenine.
Further, nucleobases comprise those disclosed in U.S. Pat. No. 3,687,808, those disclosed in ‘The Concise Encyclopedia of Polymer Science and Engineering’, pages 858-859, Kroschwitz, J. I., ed. John Wiley & Sons, 1990, those disclosed by Englisch et al., Angewandle Chemie, International Edition’, 1991, 30, page 613, and those disclosed by Sanghvi, Y. S., Chapter 15, Antisense Research and Applications’, pages 289-302, Crooke, S. T. and Lebleu, B. ea., CRC Press, 1993. Certain of these nucleobases are particularly useful for increasing the binding affinity of the oligomeric compounds of the invention. These include 5-substituted pyrimidines, 6-azapyrimidines and N-2, N-6 and 0-6 substituted purines, comprising 2-aminopropyladenine, 5-propynyluracil and 5-propynylcytosine. 5-methylcytosine substitutions have been shown to increase nucleic acid duplex stability by 0.6-1.2<0>C (Sanghvi, Y. S., Crooke, S. T. and Lebleu, B., eds, ‘Antisense Research and Applications’, CRC Press, Boca Raton, 1993, pp. 276-278) and are presently preferred base substitutions, even more particularly when combined with 2′-O-methoxyethyl sugar modifications. Modified nucleobases are described in U.S. Pat. No. 3,687,808, as well as U.S. Pat. Nos. 4,845,205; 5,130,302; 5,134,066; 5,175,273; 5,367,066; 5,432,272; 5,457,187; 5,459,255; 5,484,908; 5,502,177; 5,525,711; 5,552,540; 5,587,469; 5,596,091; 5,614,617; 5,750,692, and 5,681,941, each of which is herein incorporated by reference.
In some embodiments, the inhibitory nucleic acids are chemically linked to one or more moieties or conjugates that enhance the activity, cellular distribution, or cellular uptake of the oligonucleotide. Such moieties comprise but are not limited to, lipid moieties such as a cholesterol moiety (Letsinger (1989) Proc. Natl. Acad. Sci. USA 86, 6553-6556), cholic acid (Manoharan (1994) Bioorg. Med. Chem. Let. 4, 1053-1060), a thioether, e.g., hexyl-S-tritylthiol (Manoharan (1992) Ann. N. Y. Acad. Sci. 660, 306-309; Manoharan (1993) Bioorg. Med. Chem. Let. 3, 2765-2770), a thiocholesterol (Oberhauser (1992) Nucl. Acids Res. 20, 533-538), an aliphatic chain, e.g., dodecandiol or undecyl residues (Kabanov (1990) FEBS Lett. 259, 327-330; Svinarchuk (1993) Biochimie 75, 49-54), a phospholipid, e.g., di-hexadecyl-rac-glycerol or triethylammonium 1,2-di-O-hexadecyl-rac-glycero-3-H-phosphonate (Manoharan (1995) Tetrahedron Lett. 36, 3651-3654; Shea (1990) Nucl. Acids Res. 18, 3777-3783), a polyamine or a polyethylene glycol chain (Mancharan (1995) Nucleosides & Nucleotides 14, 969-973), or haracteri acetic acid (Manoharan (1995) Tetrahedron Lett. 36, 3651-3654), a palmityl moiety (Mishra (1995) Biochim. Biophys. Acta 1264, 229-237), or an octadecylamine or hexylamino-carbonyl-t oxycholesterol moiety (Crooke (1996) J. Pharmacol. Exp. Ther. 277, 923-937). See also U.S. Pat. Nos. 4,828,979; 4,948,882; 5,218,105; 5,525,465; 5,541,313; 5,545,730; 5,552,538; 5,578,717, 5,580,731; 5,580,731; 5,591,584; 5,109,124; 5,118,802; 5,138,045; 5,414,077; 5,486,603; 5,512,439; 5,578,718; 5,608,046; 4,587,044; 4,605,735; 4,667,025; 4,762,779; 4,789,737; 4,824,941; 4,835,263; 4,876,335; 4,904,582; 4,958,013; 5,082,830; 5,112,963; 5,214,136; 5,082,830; 5,112,963; 5,214,136; 5,245,022; 5,254,469; 5,258,506; 5,262,536; 5,272,250; 5,292,873; 5,317,098; 5,371,241, 5,391,723; 5,416,203, 5,451,463; 5,510,475; 5,512,667; 5,514,785; 5,565,552; 5,567,810; 5,574,142; 5,585,481; 5,587,371; 5,595,726; 5,597,696; 5,599,923; 5,599,928; 5,688,941, 8,865,677; 8,877,917 each of which is herein incorporated by reference.
These moieties or conjugates can include conjugate groups covalently bound to functional groups such as primary or secondary hydroxyl groups. Conjugate groups of the invention include intercalators, reporter molecules, polyamines, polyamides, polyethylene glycols, polyethers, groups that enhance the haracterization properties of oligomers, and groups that enhance the pharmacokinetic properties of oligomers. Typical conjugate groups include cholesterols, lipids, phospholipids, biotin, phenazine, folate, phenanthridine, anthraquinone, acridine, fluoresceins, rhodamines, coumarins, and dyes. Groups that enhance the haracterization properties, in the context of this invention, include groups that improve uptake, enhance resistance to degradation, and/or strengthen sequence-specific hybridization with the target nucleic acid. Groups that enhance the pharmacokinetic properties, in the context of this invention, include groups that improve uptake, distribution, metabolism or excretion of the compounds of the present invention. Representative conjugate groups are disclosed in International Patent Application No. PCT/US92/09196, filed Oct. 23, 1992, and U.S. Pat. No. 6,287,860, which are incorporated herein by reference. Conjugate moieties include, but are not limited to, lipid moieties such as a cholesterol moiety, cholic acid, a thioether, e.g., hexyl-5-tritylthiol, a thiocholesterol, an aliphatic chain, e.g., dodecandiol or undecyl residues, a phospholipid, e.g., di-hexadecyl-rac-glycerol or triethylammonium 1,2-di-O-hexadecyl-rac-glycero-3-H-phosphonate, a polyamine or a polyethylene glycol chain, or haracteri acetic acid, a palmityl moiety, or an octadecylamine or hexylamino-carbonyl-oxy cholesterol moiety. See, e.g., U.S. Pat. Nos. 4,828,979; 4,948,882; 5,218,105; 5,525,465; 5,541,313; 5,545,730; 5,552,538; 5,578,717, 5,580,731; 5,580,731; 5,591,584; 5,109,124; 5,118,802; 5,138,045; 5,414,077; 5,486,603; 5,512,439; 5,578,718; 5,608,046; 4,587,044; 4,605,735; 4,667,025; 4,762,779; 4,789,737; 4,824,941; 4,835,263; 4,876,335; 4,904,582; 4,958,013; 5,082,830; 5,112,963; 5,214,136; 5,082,830; 5,112,963; 5,214,136; 5,245,022; 5,254,469; 5,258,506; 5,262,536; 5,272,250; 5,292,873; 5,317,098; 5,371,241, 5,391,723; 5,416,203, 5,451,463; 5,510,475; 5,512,667; 5,514,785; 5,565,552; 5,567,810; 5,574,142; 5,585,481; 5,587,371; 5,595,726; 5,597,696; 5,599,923; 5,599,928 and 5,688,941.
The inhibitory nucleic acids useful in the present methods are sufficiently complementary to the target nucleic acid, i.e., hybridize sufficiently well and with sufficient specificity, to give the desired effect. “Complementary” refers to the capacity for pairing, through hydrogen bonding, between two sequences comprising naturally or non-naturally occurring bases or analogs thereof. For example, if a base at one position of an inhibitory nucleic acid is capable of hydrogen bonding with a base at the corresponding position of a nucleic acid, then the bases are considered to be complementary to each other at that position. 100% complementarity is not required.
In some embodiments, the location on a target nucleic acid to which an inhibitory nucleic acid hybridizes is defined as a target region to which a protein binding partner binds. These regions can be identified by reviewing the data submitted herewith in Appendix I and identifying regions that are enriched in the dataset; these regions are likely to include the protein binding sequences. Routine methods can be used to design an inhibitory nucleic acid that binds to this sequence with sufficient specificity. In some embodiments, the methods include using bioinformatics methods known in the art to identify regions of secondary structure, e.g., one, two, or more stem-loop structures, or pseudoknots, and selecting those regions to target with an inhibitory nucleic acid.
While the specific sequences of certain exemplary target segments are set forth herein, one of skill in the art will recognize that these serve to illustrate and describe particular embodiments within the scope of the present invention. Additional target segments are readily identifiable by one having ordinary skill in the art in view of this disclosure. Target segments 5-500 nucleotides in length comprising a stretch of at least five (5) consecutive nucleotides within the protein binding region, or immediately adjacent thereto, are considered to be suitable for targeting as well. Target segments can include sequences that comprise at least the 5 consecutive nucleotides from the 5′-terminus of one of the protein binding regions (the remaining nucleotides being a consecutive stretch of the same RNA beginning immediately upstream of the 5′-terminus of the binding segment and continuing until the inhibitory nucleic acid contains about 5 to about 100 nucleotides). Similarly, preferred target segments are represented by RNA sequences that comprise at least the 5 consecutive nucleotides from the 3′-terminus of one of the illustrative preferred target segments (the remaining nucleotides being a consecutive stretch of the same nucleic acid beginning immediately downstream of the 3′-terminus of the target segment and continuing until the inhibitory nucleic acid contains about 5 to about 100 nucleotides). One having skill in the art armed with the sequences provided herein will be able, without undue experimentation, to identify further preferred protein binding regions to target.
Once one or more target regions, segments or sites have been identified, inhibitory nucleic acid compounds are chosen that are sufficiently complementary to the target, i.e., that hybridize sufficiently well and with sufficient specificity (i.e., do not substantially bind to other non-target RNAs), to give the desired effect.
Making and Using Inhibitory Nucleic Acids
The inhibitory nucleic acids used to practice the methods described herein, whether RNA, cDNA, genomic DNA, vectors, viruses or hybrids thereof, can be isolated from a variety of sources, genetically engineered, amplified, and/or expressed, generated recombinantly or synthetically by well-known chemical synthesis techniques, as described in, e.g., Adams (1983) J. Am. Chem. Soc. 105:661; Belousov (1997) Nucleic Acids Res. 25:3440-3444; Frenkel (1995) Free Radic. Biol. Med. 19:373-380; Blommers (1994) Biochemistry 33:7886-7896; Narang (1979) Meth. Enzymol. 68:90; Brown (1979) Meth. Enzymol. 68:109; Beaucage (1981) Tetra. Lett. 22:1859; Maier (2000) Org Lett 2(13):1819-1822; Egeland (2005) Nucleic Acids Res 33(14):e125; Krotz (2005) Pharm Dev Technol 10(2):283-90 U.S. Pat. No. 4,458,066. Recombinant nucleic acid sequences can be individually isolated or cloned and tested for a desired activity. Any recombinant expression system can be used, including e.g. in vitro bacterial, fungal, mammalian, yeast, insect or plant cell expression systems.
Alternatively, recombinantly produced Pla2g5 inhibitory nucleic acids can be used. Nucleic acid sequences encoding a Pla2g5 inhibitory nucleic acid can be inserted into delivery vectors and expressed from transcription units within the vectors, e.g., in host cells. The recombinant vectors can be DNA plasmids or viral vectors. Generation of the vector construct can be accomplished using any suitable genetic engineering techniques well known in the art, including, without limitation, the standard techniques of PCR, oligonucleotide synthesis, restriction endonuclease digestion or “seamless cloning”, ligation, transformation, plasmid purification, and DNA sequencing, for example as described in Sambrook et al. “Molecular Cloning: A Laboratory Manual.” (1989)), Coffin et al. (Retroviruses. (1997)) and “RNA Viruses: A Practical Approach” (Alan J. Cann, Ed., Oxford University Press, (2000)). “Seamless cloning” allows joining of multiple fragments of nucleic acids in a single, isothermal reaction (Gibson (2009) Nat Methods 6:343-345; Werner (2012) Bioeng Bugs 3:38-43; Sanjana (2012) Nat Protoc 7:171-192). As will be apparent to one of ordinary skill in the art, a variety of suitable vectors are available for transferring nucleic acids encoding Pla2g5 inhibitory nucleic acids into cells. The selection of an appropriate vector to deliver nucleic acids and optimization of the conditions for insertion of the selected expression vector into the cell, are within the scope of one of ordinary skill in the art without the need for undue experimentation. Viral vectors comprise a nucleotide sequence having sequences for the production of recombinant virus in a packaging cell. Viral vectors expressing nucleic acids encoding Pla2g5 inhibitory nucleic acids can be constructed based on viral backbones including, but not limited to, a retrovirus, lentivirus, adenovirus, adeno-associated virus, pox virus or alphavirus (Warnock (2011) Methods in Molecular Biology 737:1-25). The recombinant vectors capable of expressing the nucleic acids can be delivered as described herein, and persist in target cells (e.g., stable transformants).
The present methods can include, for example, by administering a recombinant or synthetic Pla2g5 inhibitory nucleic acid into a macrophage produced as described herein. Inhibitory nucleic acids for use in practicing the methods described herein and that are complementary to Pla2g5 can include those which inhibit post-transcriptional processing of Pla2g5 such as inhibitors of mRNA translation (antisense), agents of RNA interference (RNAi), catalytically active RNA molecules (ribozymes), and RNAs that bind proteins and other molecular ligands (aptamers).
For further disclosure regarding inhibitory nucleic acids, please see US2010/0317718 (antisense oligos); US2010/0249052 (double-stranded ribonucleic acid (dsRNA)); US2009/0181914 and US2010/0234451 (LNAs); US2007/0191294 (siRNA analogues); US2008/0249039 (modified siRNA); and WO2010/129746 and WO2010/040112 (inhibitory nucleic acids).
Antisense
In some embodiments, the inhibitory nucleic acids are antisense oligonucleotides. Antisense oligonucleotides are typically designed to block expression of a DNA or RNA target by binding to the target and halting expression at the level of transcription, translation, or splicing. Antisense oligonucleotides of the present invention are complementary nucleic acid sequences designed to hybridize under stringent conditions to Pla2g5. Thus, oligonucleotides are chosen that are sufficiently complementary to the target, i.e., that hybridize sufficiently well and with sufficient specificity, to give the desired effect, while striving to avoid significant off-target effects i.e. must not directly bind to, or directly significantly affect expression levels of, transcripts other than the intended target. The optimal length of the antisense oligonucleotide may very but it should be as short as possible while ensuring that its target sequence is unique in the transcriptome i.e. antisense oligonucleotides may be as short as 12-mers (Seth (2009) J Med Chem 52:10-13) to 18-22 nucleotides in length.
In the context of this invention, hybridization means hydrogen bonding, which may be Watson-Crick, Hoogsteen or reversed Hoogsteen hydrogen bonding, between complementary nucleoside or nucleotide bases. For example, adenine and thymine are complementary nucleobases which pair through the formation of hydrogen bonds. Complementary, as used herein, refers to the capacity for precise pairing between two nucleotides. For example, if a nucleotide at a certain position of an oligonucleotide is capable of hydrogen bonding with a nucleotide at the same position of a DNA or RNA molecule, then the oligonucleotide and the DNA or RNA are considered to be complementary to each other at that position. The oligonucleotide and the DNA or RNA are complementary to each other when a sufficient number of corresponding positions in each molecule are occupied by nucleotides which can hydrogen bond with each other. Thus, “specifically hybridizable” and “complementary” are terms which are used to indicate a sufficient degree of complementarity or precise pairing such that stable and specific binding occurs between the oligonucleotide and the DNA or RNA target.
It is understood in the art that a complementary nucleic acid sequence need not be 100% complementary to that of its target nucleic acid to be specifically hybridisable. A complementary nucleic acid sequence of the invention is specifically hybridisable when binding of the sequence to the target DNA or RNA molecule interferes with the normal function of the target DNA or RNA to cause a loss of activity, and there is a sufficient degree of complementarity to avoid non-specific binding of the sequence to non-target sequences under conditions in which specific binding is desired, i.e., under physiological conditions in the case of in vivo assays or therapeutic treatment, and in the case of in vitro assays, under conditions in which the assays are performed under suitable conditions of stringency. The antisense oligonucleotides useful in the methods described herein have at least 80% sequence complementarity to a target region within the target nucleic acid, e.g., 90%, 95%, or 100% sequence complementarity to the target region within Pla2g5 (e.g., a target region comprising the seed sequence). Percent complementarity of an antisense compound with a region of a target nucleic acid can be determined routinely using basic local alignment search tools (BLAST programs) (Altschul (1990) J. Mol. Biol. 215, 403-410; Zhang and Madden (1997) Genome Res. 7, 649-656). The specificity of an antisense oligonucleotide can also be determined routinely using BLAST program against the entire genome of a given species
For example, stringent salt concentration will ordinarily be less than about 750 mM NaCl and 75 mM trisodium citrate, preferably less than about 500 mM NaCl and 50 mM trisodium citrate, and more preferably less than about 250 mM NaCl and 25 mM trisodium citrate. Low stringency hybridization can be obtained in the absence of organic solvent, e.g., formamide, while high stringency hybridization can be obtained in the presence of at least about 35% formamide, and more preferably at least about 50% formamide. Stringent temperature conditions will ordinarily include temperatures of at least about 30° C., more preferably of at least about 37° C., and most preferably of at least about 42° C. Varying additional parameters, such as hybridization time, the concentration of detergent, e.g., sodium dodecyl sulfate (SDS), and the inclusion or exclusion of carrier DNA, are well known to those skilled in the art. Various levels of stringency are accomplished by combining these various conditions as needed. In a preferred embodiment, hybridization will occur at 30° C. in 750 mM NaCl, 75 mM trisodium citrate, and 1% SDS. In a more preferred embodiment, hybridization will occur at 37° C. in 500 mM NaCl, 50 mM trisodium citrate, 1% SDS, 35% formamide, and 100 μg/ml denatured salmon sperm DNA (ssDNA). In a most preferred embodiment, hybridization will occur at 42° C. in 250 mM NaCl, 25 mM trisodium citrate, 1% SDS, 50% formamide, and 200 μg/ml ssDNA. Useful variations on these conditions will be readily apparent to those skilled in the art. For most applications, washing steps that follow hybridization will also vary in stringency. Wash stringency conditions can be defined by salt concentration and by temperature. As above, wash stringency can be increased by decreasing salt concentration or by increasing temperature. For example, stringent salt concentration for the wash steps will preferably be less than about 30 mM NaCl and 3 mM trisodium citrate, and most preferably less than about 15 mM NaCl and 1.5 mM trisodium citrate. Stringent temperature conditions for the wash steps will ordinarily include a temperature of at least about 25° C., more preferably of at least about 42° C., and even more preferably of at least about 68° C. In a preferred embodiment, wash steps will occur at 25° C. in 30 mM NaCl, 3 mM trisodium citrate, and 0.1% SDS. In a more preferred embodiment, wash steps will occur at 42° C. in 15 mM NaCl, 1.5 mM trisodium citrate, and 0.1% SDS. In a more preferred embodiment, wash steps will occur at 68° C. in 15 mM NaCl, 1.5 mM trisodium citrate, and 0.1% SDS. Additional variations on these conditions will be readily apparent to those skilled in the art. Hybridization techniques are well known to those skilled in the art and are described, for example, in Benton and Davis (Science 196:180, 1977); Grunstein and Hogness (Proc. Natl. Acad. Sci., USA 72:3961, 1975); Ausubel et al. (Current Protocols in Molecular Biology, Wiley Interscience, New York, 2001); Berger and Kimmel (Guide to Molecular Cloning Techniques, 1987, Academic Press, New York); and Sambrook et al., Molecular Cloning: A Laboratory Manual, Cold Spring Harbor Laboratory Press, New York, Hilario (2007) Methods Mol Biol 353:27-38.
Inhibitory nucleic acids for use in the methods described herein can include one or more modifications, e.g., be stabilized against nucleolytic degradation such as by the incorporation of a modification, e.g., a nucleotide modification. For example, inhibitory nucleic acids can include a phosphorothioate at least the first, second, or third internucleotide linkage at the 5′ or 3′ end of the nucleotide sequence. As another example, inhibitory nucleic acids can include a 2′-modified nucleotide, e.g., a 2′-deoxy, 2′-deoxy-2′-fluoro, 2′-O-methyl, 2′-O-methoxyethyl (2′-O-MOE), 2′-O-aminopropyl (2′-O-AP), 2′-O-dimethylaminoethyl (2′-O-DMAOE), 2′-O-dimethylaminopropyl (2′-O-DMAP), 2′-O-dimethylaminoethyloxyethyl (2′-O-DMAEOE), or 2′-O—N-methylacetamido (2′-O-NMA). As another example, the inhibitory nucleic acids can include at least one 2′-O-methyl-modified nucleotide, and in some embodiments, all of the nucleotides include a 2′-O-methyl modification.
Modifications
Chemical modifications, particularly the use of locked nucleic acids (LNAs) (Okiba (1997) Tetrahedron Lett 39:5401-5404; Singh (1998) Chem Commun 4:455-456), 2′-O-methoxyethyl (2′-O-MOE) (Martin (1995) Helv Chim Acta 78:486-504; You (2006) Nucleic Acids Res 34(8):e60; Owczarzy (2011) Biochem 50(43):9352-9367), constrained ethyl BNA (cET) (Murray (2012) Nucleic Acids Res 40: 6135-6143), and gapmer oligonucleotides, which contain 2-5 chemically modified nucleotides (LNA, 2′-O-MOE RNA or cET) at each terminus flanking a central 5-10 base “gap” of DNA (Monia (1993) J Biol Chem 268:14514-14522; Wahlestedt (2000) PNAS 97:5633-5638), improve antisense oligonucleotide binding affinity for the target RNA, which increases the steric block efficiency. Antisense and other compounds that hybridize to Pla2g5 are identified through experimentation, and representative sequences of these compounds are herein below identified as preferred embodiments of the invention (e.g., including but not limited to the antisense oligonucleotide or siRNAs of SEQ ID NO. 5 (AGAGAAACCUACGGAGCUA), SEQ ID NO. 6 (AGAACGCCCUGACAAACUA) SEQ ID NO. 7 (GAGAAGGGCUGCAACAUUC), or SEQ ID NO. 8 (GCACACAGUCCUACAAAUA).
Techniques for the manipulation of inhibitory nucleic acids, such as, e.g., subcloning, labeling probes (e.g., random-primer labeling using Klenow polymerase, nick translation, amplification), sequencing, hybridization and the like are well described in the scientific and patent literature, see, e.g., Sambrook et al., Molecular Cloning; A Laboratory Manual 3d ed. (2001); Current Protocols in Molecular Biology, Ausubel et al., eds. (John Wiley & Sons, Inc., New York 2010); Kriegler, Gene Transfer and Expression: A Laboratory Manual (1990); Laboratory Techniques In Biochemistry And Molecular Biology: Hybridization With Nucleic Acid Probes, Part I. Theory and Nucleic Acid Preparation, Tijssen, ed. Elsevier, N.Y. (1993).
Modified Bases/Locked Nucleic Acids (LNAs)
In some embodiments, the inhibitory nucleic acids used in the methods described herein comprise one or more modified bonds or bases. Modified bases include phosphorothioate, methylphosphonate, peptide nucleic acids, or locked nucleic acid (LNA) molecules. In some embodiments, the inhibitory nucleic acids are “locked,” i.e., comprise nucleic acid analogues in which the ribose ring is “locked” by a methylene bridge connecting the 2′-O atom and the 4′-C atom (see, e.g., Kaupinnen (2005) Drug Disc. Today 2(3):287-290; Koshkin (1998) J. Am. Chem. Soc. 120(50):13252-13253). For additional modifications see US 20100004320, US 20090298916, and US 20090143326.
The LNA molecules can be designed using any method known in the art; a number of algorithms are known, and are commercially available (e.g., exiqon.com). You (2006) Nuc. Acids. Res. 34:e60; McTigue (2004) Biochemistry 43:5388-405; and Levin (2006) Nuc. Acids. Res. 34:e142. General guidelines for designing LNAs are known in the art; for example, LNA sequences will bind very tightly to other LNA sequences, so it is preferable to avoid significant complementarity within an LNA. Contiguous runs of three or more Gs or Cs, or more than four LNA residues, should be avoided where possible (for example, it may not be possible with very short (e.g., about 9-10 nt) oligonucleotides). In some embodiments, the LNAs are xylo-LNAs.
In some embodiments, the LNA molecules can be designed to target a specific region of the nucleic acid. For example, a specific functional region can be targeted, e.g., a region comprising a known RNA localization motif (i.e., a region complementary to the target nucleic acid on which the nucleic acid acts), or a region comprising a known protein binding region, e.g., a Polycomb (e.g., Polycomb Repressive Complex 2 (PRC2), comprised of H3K27 methylase EZH2, SUZ12, and EED)) or LSD1/CoREST/REST complex binding region (Tsai (2010) Science 329(5992):689-93; and Zhao (2008) Science 322(5902):750-6; Sarma (2010) PNAS 107 (51): 22196-201). Alternatively or in addition, highly conserved regions can be targeted, e.g., regions identified by aligning sequences from disparate species such as primate (e.g., human) and rodent (e.g., mouse) and looking for regions with high degrees of identity. Percent identity can be determined routinely using basic local alignment search tools (BLAST programs) (Altschul (1990) J. Mol. Biol. 215, 403-410; Zhang and Madden (1997) Genome Res. 7, 649-656), e.g., using the default parameters.
For additional information regarding LNAs see U.S. Pat. Nos. 6,268,490; 6,734,291; 6,770,748; 6,794,499; 7,034,133; 7,053,207; 7,060,809; 7,084,125; and 7,572,582; and U.S. Pre-Grant Pub. Nos. 20100267018; 20100261175; and 20100035968; Koshkin (1998) Tetrahedron 54, 3607-3630; Obika (1998) Tetrahedron Lett. 39, 5401-5404; Jepsen (2004) Oligonucleotides 14:130-146; Kauppinen (2005) Drug Disc. Today 2(3):287-290; and Ponting (2009) Cell 136(4):629-641, and references cited therein.
See also U.S. Ser. No. 61/412,862, which is incorporated by reference herein in its entirety.
siRNA/shRNA
In some embodiments, the nucleic acid sequence that is complementary to Pla2g5 can be an interfering RNA, including but not limited to a small interfering RNA (“siRNA”) or a small hairpin RNA (“shRNA”). Methods for constructing interfering RNAs are well known in the art. For example, the interfering RNA can be assembled from two separate oligonucleotides, where one strand is the sense strand and the other is the antisense strand, wherein the antisense and sense strands are self-complementary (i.e., each strand comprises nucleotide sequence that is complementary to nucleotide sequence in the other strand; such as where the antisense strand and sense strand form a duplex or double stranded structure); the antisense strand comprises nucleotide sequence that is complementary to a nucleotide sequence in a target nucleic acid molecule or a portion thereof (i.e., an undesired gene) and the sense strand comprises nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof. Alternatively, interfering RNA is assembled from a single oligonucleotide, where the self-complementary sense and antisense regions are linked by means of nucleic acid based or non-nucleic acid-based linker(s). The interfering RNA can be a polynucleotide with a duplex, asymmetric duplex, hairpin or asymmetric hairpin secondary structure, having self-complementary sense and antisense regions, wherein the antisense region comprises a nucleotide sequence that is complementary to nucleotide sequence in a separate target nucleic acid molecule or a portion thereof and the sense region having nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof. The interfering can be a circular single-stranded polynucleotide having two or more loop structures and a stem comprising self-complementary sense and antisense regions, wherein the antisense region comprises nucleotide sequence that is complementary to nucleotide sequence in a target nucleic acid molecule or a portion thereof and the sense region having nucleotide sequence corresponding to the target nucleic acid sequence or a portion thereof, and wherein the circular polynucleotide can be processed either in vivo or in vitro to generate an active siRNA molecule capable of mediating RNA interference. RNA interference may cause translational repression and degradation of target mRNAs with imperfect complementarity or sequence-specific cleavage of perfectly complementary mRNAs.
In some embodiments, the interfering RNA coding region encodes a self-complementary RNA molecule having a sense region, an antisense region and a loop region. Such an RNA molecule when expressed desirably forms a “hairpin” structure, and is referred to herein as an “shRNA.” The loop region is generally between about 2 and about 10 nucleotides in length. In some embodiments, the loop region is from about 6 to about 9 nucleotides in length. In some embodiments, the sense region and the antisense region are between about 15 and about 20 nucleotides in length. Following post-transcriptional processing, the small hairpin RNA is converted into a siRNA by a cleavage event mediated by the enzyme Dicer, which is a member of the Rnase III family. The siRNA is then capable of inhibiting the expression of a gene with which it shares homology. After the siRNA has cleaved its target, it is released from that RNA to search for another target and can repeatedly bind and cleave new targets (Brummelkamp (2002) Science 296:550-553; Lee (2002) Nature Biotechnol., 20, 500-505; Miyagishi and Taira (2002) Nature Biotechnol 20:497-500; Paddison (2002) Genes & Dev. 16:948-958; Paul (2002) Nature Biotechnol 20, 505-508; Sui (2002) Proc. Natl. Acad. Sd. USA 99(6), 5515-5520; Yu (2002) Proc Natl Acad Sci USA 99:6047-6052; Peer and Lieberman (2011) Gen Ther 18, 1127-1133).
The target RNA cleavage reaction guided by siRNAs is highly sequence specific. In general, siRNA containing a nucleotide sequences identical to a portion of the target nucleic acid are preferred for inhibition. However, 100% sequence identity between the siRNA and the target gene is not required to practice the present invention. Thus, the invention has the advantage of being able to tolerate sequence variations that might be expected due to genetic mutation, strain polymorphism, or evolutionary divergence. For example, siRNA sequences with insertions, deletions, and single point mutations relative to the target sequence have also been found to be effective for inhibition. Alternatively, siRNA sequences with nucleotide analog substitutions or insertions can be effective for inhibition. In general the siRNAs must retain specificity for their target, i.e., must not directly bind to, or directly significantly affect expression levels of, transcripts other than the intended target. shRNAs that are constitutively expressed form promoters can ensure long-term gene silencing. Most methods commonly used for delivery of siRNAs rely on commonly used techniques for introducing an exogenous nucleic acid into a cell including calcium phosphate or calcium chloride precipitation, microinjection, DEAE-dextrin-mediated transfection, lipofection, commercially available cationic polymers and lipids and cell-penetrating peptides, electroporation or stable nucleic acid-lipid particles (SNALPs), all of which are routine in the art. siRNAs can also be conjugated to small molecules to direct binding to cell-surface receptors, such as cholesterol (Wolfrum (2007) Nat Biotechnol 25:1149-1157), alpha-tocopherol (Nishina (2008) Mol Ther 16:734-40), lithocholic acid or lauric acid (Lorenz (2004) Bioorg Med Chem Lett 14:4975-4977), polyconjugates (Rozema (2007) PNAS 104:12982-12987). A variation of conjugated siRNAs are aptamer-siRNA chimeras (McNamara (2006) Nat Biotechnol 24:1005-1015; Dassie (2009) Nat Biotechnol 27:839-849) and siRNA-fusion protein complexes, which is composed of a targeting peptide, such as an antibody fragment that recognizes a cell-surface receptor or ligand, linked to an RNA-binding peptide that can be complexed to siRNAs for targeted systemic siRNA delivery (Yao (2011) Sci Transl Med 4(130):130ra48.
Ribozymes
Trans-cleaving enzymatic nucleic acid molecules can also be used; they have shown promise as therapeutic agents for human disease (Usman & McSwiggen, (1995) Ann. Rep. Med. Chem. 30, 285-294; Christoffersen and Marr (1995) J. Med. Chem. 38, 2023-2037; Weng (2005) Mol Cancer Ther 4, 948-955; Armado (2004) Hum Gene Ther 15, 251-262; Macpherson (2005) J Gene Med 7, 552-564; Muhlbacher (2010) Curr Opin Pharamacol 10(5):551-6). Enzymatic nucleic acid molecules can be designed to cleave specific Pla2g5 targets within the background of cellular RNA. Such a cleavage event renders the Pla2g5 mRNA non-functional.
In general, enzymatic nucleic acids with RNA cleaving activity act by first binding to a target RNA. Such binding occurs through the target binding portion of an enzymatic nucleic acid which is held in close proximity to an enzymatic portion of the molecule that acts to cleave the target RNA. Thus, the enzymatic nucleic acid first recognizes and then binds a target RNA through complementary base pairing, and once bound to the correct site, acts enzymatically to cut the target RNA. Strategic cleavage of such a target RNA will destroy its ability to direct synthesis of an encoded protein. After an enzymatic nucleic acid has bound and cleaved its RNA target, it is released from that RNA to search for another target and can repeatedly bind and cleave new targets.
Several approaches such as in vitro selection (evolution) strategies (Orgel (1979) Proc. R. Soc. London B 205, 435) have been used to evolve new nucleic acid catalysts with improved properties, new functions and capable of catalyzing a variety of reactions, such as cleavage and ligation of phosphodiester linkages and amide linkages, (Joyce (1989) Gene 82, 83-87; Beaudry (1992) Science 257, 635-641; Joyce (1992) Scientific American 267, 90-97; Breaker (1994) TIBTECH 12, 268; Bartel (1993) Science 261:1411-1418; Szostak (1993) TIBS 17, 89-93; Kumar (1995) FASEB J. 9, 1183; Breaker (1996) Curr. Op. Biotech. 1, 442; Scherer (2003) Nat Biotechnol 21, 1457-1465; Berens (2015) Curr. Op. Biotech. 31, 10-15). Ribozymes can also be engineered to be allosterically activated by effector molecules (riboswitches, Liang (2011) Mol Cell 43, 915-926; Wieland (2010) Chem Biol 17, 236-242; U.S. Pat. No. 8,440,810). The development of ribozymes that are optimal for catalytic activity would contribute significantly to any strategy that employs RNA-cleaving ribozymes for the purpose of regulating gene expression. The most common ribozyme therapeutics are derived from either hammerhead or hairpin/paperclip motifs. The hammerhead ribozyme, for example, functions with a catalytic rate (kcat) of about 1 min-1 in the presence of saturating (10 rnM) concentrations of Mg2+ cofactor. An artificial “RNA ligase” ribozyme has been shown to catalyze the corresponding self-modification reaction with a rate of about 100 min-1. In addition, it is known that certain modified hammerhead ribozymes that have substrate binding arms made of DNA catalyze RNA cleavage with multiple turn-over rates that approach 100 min-1. Ribozymes can be delivered to target cells in RNA form or can be transcribed from vectors. Due to poor stability of fully-RNA ribozymes, ribozymes often require chemical modification, such as, 5′-PS backbone linkage, 2′-O-Me, 2′-deoxy-2′-C-allyl uridine, and terminal inverted 3′-3′ deoxyabasic nucleotides (Kobayashi (2005) Cancer Chemother Pharmacol 56, 329-336).
Antagomirs
In some embodiments, the antisense is an antagomir. Antagomirs are chemically modified antisense oligonucleotides that target a nucleic acid or miRNA (U.S. Pat. No. 8,937,217). For example, an antagomir for use in the methods described herein can include a nucleotide sequence sufficiently complementary to hybridize to a Pla2g5 target sequence of about 12 to 25 nucleotides, preferably about 15 to 23 nucleotides.
In general, antagomirs include a cholesterol moiety, e.g., at the 3′-end. In some embodiments, antagomirs have various modifications for Rnase protection and pharmacologic properties such as enhanced tissue and cellular uptake. For example, In addition to the modifications discussed above for antisense oligonucleotides, an antagomir can have one or more of complete or partial 2′-O-methylation of sugar and/or a phosphorothioate backbone. Phosphorothioate modifications provide protection against Rnase activity and their lipophilicity contributes to enhanced tissue uptake. In some embodiments, the antagomir cam include six phosphorothioate backbone modifications; two phosphorothioates are located at the 5′-end and four at the 3′-end. See, e.g., Krutzfeldt (2005) Nature 438, 685-689; Czech (2006) N Engl J Med, 354:1194-1195; Robertson (2010) Silence. 1:10; Marquez and McCaffrey (2008) Hum Gene Ther., 19(1):27-38; van Rooij (2008) Circ Res. 103(9):919-928; and Liu (2008) Int. J. Mol. Sci. 9:978-999; (Ebert (2010) RNA 16, 2043-2050). Antagomirs useful in the present methods can also be modified with respect to their length or otherwise the number of nucleotides making up the antagomir. The antagomirs must retain specificity for their target, i.e., must not directly bind to, or directly significantly affect expression levels of, transcripts other than the intended target.
In some embodiments, the inhibitory nucleic acid is locked and includes a cholesterol moiety (e.g., a locked antagomir; Krutzfeldt (2005) Nature 438, 685-689).
In some embodiments, the antisense is a miRNA sponge or a variation of miRNA sponge, such as target mimics (Franco-Zorrilla (2007) Nat Genet 39:1033-1037), decoys (Care (2007) Nat Med 13:613-618, miRNA target sequences (Gentner (2009) Nat Methods 6:63-66), miRNA erasers (Sayed (2008) Mol Biol Cell 19:3272-3282), and lentivirus-mediated antagomirs (Scherr (2007) Nucleic Acid Res 35:e149). Sponge constructs typically contain 4-10 binding sites separated by a few nucleotides each. The efficacy of miRNA sponges depends on affinity and avidity of binding sites, as well as the concentration of sponge RNAs relative to the concentration of the miRNA.
CRISPR Pla2g5 Gene Editing Complexes
The present methods include the use of CRISPR Pla2g5 gene editing complexes. The methods can include the use of expression vectors for transfection and expression of a Cas9 protein and suitable guide RNAs targeting Pla2g5. Alternatively, or in addition, the methods can include the use of purified Cas9 proteins complexed with suitable guide RNAs targeting Pla2g5.
Nucleic Acids Encoding a CRISPR Pla2g5 Gene Editing Complex
The present methods include the delivery of nucleic acids encoding a CRISPR Pla2g5 gene editing complex. The gene editing complex includes a Cas9 editing enzyme and one or more guide RNAs directing the editing enzyme to Pla2g5.
Guide RNAs Directing the Editing Enzyme to Pla2g5
The gene editing complex also includes guide RNAs directing the editing enzyme to Pla2g5, i.e., comprising a sequence that is complementary to the sequence of a nucleic acid encoding Pla2g5, and that include a PAM sequence that is targetable by the co-administered Cas9 editing enzyme. In some embodiments, the precursor sequence is targeted by the guide RNA., i.e., comprising a sequence that is complementary to the sequence of a nucleic acid encoding Pla2g5. In some embodiments, the precursor sequence is targeted by the guide RNA.
The gene encoding the human Pla2g5 precursor is at nucleotides 20028350-20091901 of chromosome 11, Reference GRCh38.p7 Primary Assembly (see GenBank Acc. No. NG_032045.1).
Other Cas9s from other species can also be used, including those shown in Table 1. Suitable target sequences for use with those Cas9s can readily be determined using known methods.
TABLE 1
Exemplary Cas9s
Species/Variant of Cas9
PAM Sequence
SpCas9 D1135E variant
NGG (reduced NAG binding)
SpCas9 VRER variant
NGCG
SpCas9 EQR variant
NGAG
SpCas9 VQR variant
NGAN or NGNG
Streptococcus thermophilus (ST)
NNAGAAW
Treponema denticola (TD)
NAAAAC
Streptococcus pyogenes (SP); SpCas9
NGG
Staphylococcus aureus (SA); SaCas9
NNGRRT or NNGRR(N)
Neisseria haracteriza (NM)
NNNNGATT
Cas9 Editing Enzymes
The methods include the delivery of Cas9 editing enzymes to the cells. The editing enzymes can include one or more of SpCas9 D1135E variant; SpCas9 VRER variant; SpCas9 EQR variant; SpCas9 VQR variant; Streptococcus thermophilus (ST) Cas9 (StCas9); Treponema denticola (TD) (TdCas9); Streptococcus pyogenes (SP) (SpCas9); Staphylococcus aureus (SA) Cas9 (SaCas9); or Neisseria haracteriza (NM) Cas9 (NmCas9), as well as variants thereof that are at least 80%, 85%, 90%, 95%, 99% or 100% identical thereto that retain at least one function of the parent case, e.g., the ability to complex with a gRNA, bind to target DNA specified by the gRNA, and alter the sequence of the target DNA.
To determine the percent identity of two sequences, the sequences are aligned for optimal comparison purposes (gaps are introduced in one or both of a first and a second amino acid or nucleic acid sequence as required for optimal alignment, and non-homologous sequences can be disregarded for comparison purposes). The length of a reference sequence aligned for comparison purposes is at least 80% (in some embodiments, about 85%, 90%, 95%, or 100% of the length of the reference sequence) is aligned. The nucleotides or residues at corresponding positions are then compared. When a position in the first sequence is occupied by the same nucleotide or residue as the corresponding position in the second sequence, then the molecules are identical at that position. The percent identity between the two sequences is a function of the number of identical positions shared by the sequences, taking into account the number of gaps, and the length of each gap, which need to be introduced for optimal alignment of the two sequences.
The comparison of sequences and determination of percent identity between two sequences can be accomplished using a mathematical algorithm. For example, the percent identity between two amino acid sequences can be determined using the Needleman and Wunsch ((1970) J. Mol. Biol. 48:444-453) algorithm which has been incorporated into the GAP program in the GCG software package, using a Blossum 62 scoring matrix with a gap penalty of 12, a gap extend penalty of 4, and a frameshift gap penalty of 5.
The PAM sequences of these Cas9s are listed in Table 1, above. The sequences of the Cas9s are known in the art; see, e.g., Kleinstiver et al., Nature. 2015 Jul. 23; 523(7561): 481-485; WO 2016/141224; U.S. Pat. No. 9,512,446; US-2014-0295557; WO 2014/204578; and WO 2014/144761. The methods can also include the use of the other previously described variants of the SpCas9 platform (e.g., truncated sgRNAs (Tsai et al., Nat Biotechnol 33, 187-197 (2015); Fu et al., Nat Biotechnol 32, 279-284 (2014)), nickase mutations (Mali et al., Nat Biotechnol 31, 833-838 (2013); Ran et al., Cell 154, 1380-1389 (2013)), FokI-dCas9 fusions (Guilinger et al., Nat Biotechnol 32, 577-582 (2014); Tsai et al., Nat Biotechnol 32, 569-576 (2014); WO2014144288).
The SpCas9 wild type sequence is as follows:
(SEQ ID NO: 9)
MDKKYSIGLDIGTNSVGWAVITDEYKVPSKKFKVLGNTDRHSIKKNLIGA
LLFDSGETAEATRLKRTARRRYTRRKNRICYLQEIFSNEMAKVDDSFFHR
LEESFLVEEDKKHERHPIFGNIVDEVAYHEKYPTIYHLRKKLVDSTDKAD
LRLIYLALAHMIKFRGHFLIEGDLNPDNSDVDKLFIQLVQTYNQLFEENP
INASGVDAKAILSARLSKSRRLENLIAQLPGEKKNGLFGNLIALSLGLTP
NFKSNFDLAEDAKLQLSKDTYDDDLDNLLAQIGDQYADLFLAAKNLSDAI
LLSDILRVNTEITKAPLSASMIKRYDEHHQDLTLLKALVRQQLPEKYKEI
FFDQSKNGYAGYIDGGASQEEFYKFIKPILEKMDGTEELLVKLNREDLLR
KQRTFDNGSIPHQIHLGELHAILRRQEDFYPFLKDNREKIEKILTFRIPY
YVGPLARGNSRFAWMTRKSEETITPWNFEEVVDKGASAQSFIERMTNFDK
NLPNEKVLPKHSLLYEYFTVYNELTKVKYVTEGMRKPAFLSGEQKKAIVD
LLFKTNRKVTVKQLKEDYFKKIECFDSVEISGVEDRFNASLGTYHDLLKI
IKDKDFLDNEENEDILEDIVLTLTLFEDREMIEERLKTYAHLFDDKVMKQ
LKRRRYTGWGRLSRKLINGIRDKQSGKTILDFLKSDGFANRNFMQLIHDD
SLTFKEDIQKAQVSGQGDSLHEHIANLAGSPAIKKGILQTVKVVDELVKV
MGRHKPENIVIEMARENQTTQKGQKNSRERMKRIEEGIKELGSQILKEHP
VENTQLQNEKLYLYYLQNGRDMYVDQELDINRLSDYDVDHIVPQSFLKDD
SIDNKVLTRSDKNRGKSDNVPSEEVVKKMKNYWRQLLNAKLITQRKFDNL
TKAERGGLSELDKAGFIKRQLVETRQITKHVAQILDSRMNTKYDENDKLI
REVKVITLKSKLVSDFRKDFQFYKVREINNYHHAHDAYLNAVVGTALIKK
YPKLESEFVYGDYKVYDVRKMIAKSEQEIGKATAKYFFYSNIMNFFKTEI
TLANGEIRKRPLIETNGETGEIVWDKGRDFATVRKVLSMPQVNIVKKTEV
QTGGFSKESILPKRNSDKLIARKKDWDPKKYGGFDSPTVAYSVLVVAKVE
KGKSKKLKSVKELLGITIMERSSFEKNPIDFLEAKGYKEVKKDLIIKLPK
YSLFELENGRKRMLASAGELQKGNELALPSKYVNFLYLASHYEKLKGSPE
DNEQKQLFVEQHKHYLDEIIEQISEFSKRVILADANLDKVLSAYNKHRDK
PIREQAENIIHLFTLTNLGAPAAFKYFDTTIDRKRYTSTKEVLDATLIHQ
SITGLYETRIDLSQLGGD
The SaCas9 wild type sequence is as follows:
(SEQ ID NO: 10)
MKRNYILGLDIGITSVGYGIIDYETRDVIDAGVRLFKEANVENNEGRRSK
RGARRLKRRRRHRIQRVKKLLFDYNLLTDHSELSGINPYEARVKGLSQKL
SEEEFSAALLHLAKRRGVHNVNEVEEDTGNELSTKEQISRNSKALEEKYV
AELQLERLKKDGEVRGSINRFKTSDYVKEAKQLLKVQKAYHQLDQSFIDT
YIDLLETRRTYYEGPGEGSPFGWKDIKEWYEMLMGHCTYFPEELRSVKYA
YNADLYNALNDLNNLVITRDENEKLEYYEKFQIIENVFKQKKKPTLKQIA
KEILVNEEDIKGYRVTSTGKPEFTNLKVYHDIKDITARKEIIENAELLDQ
IAKILTIYQSSEDIQEELTNLNSELTQEEIEQISNLKGYTGTHNLSLKAI
NLILDELWHTNDNQIAIFNRLKLVPKKVDLSQQKEIPTTLVDDFILSPVV
KRSFIQSIKVINAIIKKYGLPNDIIIELAREKNSKDAQKMINEMQKRNRQ
TNERIEEIIRTTGKENAKYLIEKIKLHDMQEGKCLYSLEAIPLEDLLNNP
FNYEVDHIIPRSVSFDNSFNNKVLVKQEENSKKGNRTPFQYLSSSDSKIS
YETFKKHILNLAKGKGRISKTKKEYLLEERDINRFSVQKDFINRNLVDTR
YATRGLMNLLRSYFRVNNLDVKVKSINGGFTSFLRRKWKFKKERNKGYKH
HAEDALIIANADFIFKEWKKLDKAKKVMENQMFEEKQAESMPEIETEQEY
KEIFITPHQIKHIKDFKDYKYSHRVDKKPNRELINDTLYSTRKDDKGNTL
IVNNLNGLYDKDNDKLKKLINKSPEKLLMYHHDPQTYQKLKLIMEQYGDE
KNPLYKYYEETGNYLTKYSKKDNGPVIKKIKYYGNKLNAHLDITDDYPNS
RNKVVKLSLKPYRFDVYLDNGVYKFVTVKNLDVIKKENYYEVNSKCYEEA
KKLKKISNQAEFIASFYNNDLIKINGELYRVIGVNNDLLNRIEVNMIDIT
YREYLENMNDKRPPRIIKTIASKTQSIKKYSTDILGNLYEVKSKKHPQII
KKG
See also Hou, Z. et al. Efficient genome engineering in human pluripotent stem cells using Cas9 from Neisseria haracteriza. Proc Natl Acad Sci USA (2013); Fonfara, I. et al. Phylogeny of Cas9 determines functional exchangeability of dual-RNA and Cas9 among orthologous type II CRISPR-Cas systems. Nucleic Acids Res 42, 2577-2590 (2014); Esvelt, K. M. et al. Orthogonal Cas9 proteins for RNA-guided gene regulation and editing. Nat Methods 10, 1116-1121 (2013); Cong, L. et al. Multiplex genome engineering using CRISPR/Cas systems. Science 339, 819-823 (2013); Horvath, P et al. Diversity, activity, and evolution of CRISPR loci in Streptococcus thermophilus. J Bacteriol 190, 1401-1412 (2008).
As noted above, the Cas9 can be delivered as a purified protein (e.g., a recombinantly produced purified protein, prefolded and optionally complexed with the sgRNA) or as a nucleic acid encoding the Cas9, e.g., an expression construct. Purified Cas9 proteins can be produced using methods known in the art, e.g., expressed in prokaryotic or eukaryotic cells and purified using standard methodology. See, e.g., Liang et al., Journal of Biotechnology 208:44-53 (2015); Kim et al., Genome Res. 2014 June; 24(6): 1012-1019. Efficiency of protein delivery can be enhanced, e.g., using electroporation (see, e.g., Wang et al., Journal of Genetics and Genomics 43(5):319-327 (2016)); cationic or lipophilic carriers (see, e.g., Yu et al., Biotechnol Lett. 2016; 38: 919-929; Zuris et al., Nat Biotechnol. 33(1):73-80 (2015)); or even lentiviral packaging particles (see, e.g., Choi et al., Gene Therapy 23, 627-633 (2016)).
CRISPR Expression Constructs
Expression constructs encoding one or both of guide RNAs and/or Cas9 editing enzymes can be administered in any effective carrier, e.g., any formulation or composition capable of effectively delivering the component gene to cells. Approaches include insertion of the gene in viral vectors, including recombinant retroviruses, adenovirus, adeno-associated virus, lentivirus, and herpes simplex virus-1, or recombinant bacterial or eukaryotic plasmids. Viral vectors transfect cells directly; plasmid DNA can be delivered naked or with the help of, for example, cationic liposomes (lipofectamine) or derivatized (e.g., antibody conjugated), polylysine conjugates, haracteri S, artificial viral envelopes or other such intracellular carriers, as well as direct injection of the gene construct or CaPO4 precipitation.
A preferred approach for introduction of nucleic acid into a cell is by use of a viral vector containing nucleic acid, e.g., a cDNA. Infection of cells with a viral vector has the advantage that a large proportion of the targeted cells can receive the nucleic acid. Additionally, molecules encoded within the viral vector, e.g., by a cDNA contained in the viral vector, are expressed efficiently in cells that have taken up viral vector nucleic acid.
Retrovirus vectors and adeno-associated virus vectors can be used as a recombinant gene delivery system for the transfer of exogenous genes. These vectors provide efficient delivery of genes into cells, and the transferred nucleic acids are stably integrated into the chromosomal DNA of the host cell. The development of specialized cell lines (termed “packaging cells”) which produce only replication-defective retroviruses has increased the utility of retroviruses for gene therapy, and defective retroviruses are characterized for use in gene transfer for gene therapy purposes (for a review see Miller, Blood 76:271 (1990)). A replication defective retrovirus can be packaged into virions, which can be used to infect a target cell through the use of a helper virus by standard techniques. Protocols for producing recombinant retroviruses and for infecting cells in vitro with such viruses can be found in Ausubel, et al., eds., Current Protocols in Molecular Biology, Greene Publishing Associates, (1989), Sections 9.10-9.14, and other standard laboratory manuals. Examples of suitable retroviruses include pLJ, pZIP, pWE and pEM which are known to those skilled in the art. Examples of suitable packaging virus lines for preparing both ecotropic and amphotropic retroviral systems include ΨCrip, ΨCre, Ψ2 and ΨAm. Retroviruses have been used to introduce a variety of genes into many different cell types, including epithelial cells, in vitro (see for example Eglitis, et al. (1985) Science 230:1395-1398; Danos and Mulligan (1988) Proc. Natl. Acad. Sci. USA 85:6460-6464; Wilson et al. (1988) Proc. Natl. Acad. Sci. USA 85:3014-3018; Armentano et al. (1990) Proc. Natl. Acad. Sci. USA 87:6141-6145; Huber et al. (1991) Proc. Natl. Acad. Sci. USA 88:8039-8043; Ferry et al. (1991) Proc. Natl. Acad. Sci. USA 88:8377-8381; Chowdhury et al. (1991) Science 254:1802-1805; van Beusechem et al. (1992) Proc. Natl. Acad. Sci. USA 89:7640-7644; Kay et al. (1992) Human Gene Therapy 3:641-647; Dai et al. (1992) Proc. Natl. Acad. Sci. USA 89:10892-10895; Hwu et al. (1993) J. Immunol. 150:4104-4115; U.S. Pat. Nos. 4,868,116; 4,980,286; PCT Application WO 89/07136; PCT Application WO 89/02468; PCT Application WO 89/05345; and PCT Application WO 92/07573).
As demonstrated herein, a lentiviral CRISPR-Cas9 targeting system provided high and tumor-specific expression of Cas9, the corresponding high Pla2g5 editing efficacy in tumor tissues, while lacking general toxicity or neurotoxicity. Lentiviral vectors transduce dividing as well as quiescent cells. This can be viewed as a major advantage with respect to gene therapy for tumors in general, as within a short treatment window most tumor cells (and especially GSC) do not divide. Therapeutic use of the lentiviral editing approach can be a legitimate alternative to other viral systems, as high viral titers can be produced, nonproliferating cells that are especially abundant in the walls of the tumor cavity after surgery can be transduced, and transduction efficacies are very high. An additional advantage of a locally applied vesicular stomatitis virus glycoprotein (VSV-G) pseudotyped lentivirus is its inactivation by human serum that would reduce systemic effects. To further reduce neurotrophism, and enhance selective tropism for glioma and GSC, the commonly bound envelope glycoprotein of VSV can be replaced with a more selective variant glycoprotein of lymphocytic choriomeningitis virus (LCMV-GP). LCMV-GP is not cytotoxic when injected locally or systemically, can be packaged with other components of the CRISPR-Cas9 system, and efficiently transduces solid glioma tissues as well as infiltrating tumor cells.
Another viral gene delivery system useful in the present methods utilizes adenovirus-derived vectors. The genome of an adenovirus can be manipulated, such that it encodes and expresses a gene product of interest but is inactivated in terms of its ability to replicate in a normal lytic viral life cycle. See, for example, Berkner et al., BioTechniques 6:616 (1988); Rosenfeld et al., Science 252:431-434 (1991); and Rosenfeld et al., Cell 68:143-155 (1992). Suitable adenoviral vectors derived from the adenovirus strain Ad type 5 dl324 or other strains of adenovirus (e.g., Ad2, Ad3, or Ad7 etc.) are known to those skilled in the art. Recombinant adenoviruses can be advantageous in certain circumstances, in that they are not capable of infecting non-dividing cells and can be used to infect a wide variety of cell types, including epithelial cells (Rosenfeld et al., (1992) supra). Furthermore, the virus particle is relatively stable and amenable to purification and concentration, and as above, can be modified so as to affect the spectrum of infectivity. Additionally, introduced adenoviral DNA (and foreign DNA contained therein) is not integrated into the genome of a host cell but remains episomal, thereby avoiding potential problems that can occur as a result of insertional mutagenesis in situ, where introduced DNA becomes integrated into the host genome (e.g., retroviral DNA). Moreover, the carrying capacity of the adenoviral genome for foreign DNA is large (up to 8 kilobases) relative to other gene delivery vectors (Berkner et al., supra; Haj-Ahmand and Graham, J. Virol. 57:267 (1986).
Pla2g5 genome-editing vectors based on recombinant Adenovirus-5 (Ad5): Ad5 have many advantages for this purpose, including non-integration, lack of insertional mutagenesis, high-efficiency transduction, and accommodation of large expression cassettes; these vectors have also been utilized in multiple clinical trials.
Helper-dependent (HDAd) vectors can also be produced with all adenoviral sequences deleted except the origin of DNA replication at each end of the viral DNA along with packaging signal at 5-prime end of the genome downstream of the left packaging signal. HDAd vectors are constructed and propagated in the presence of a replication-competent helper adenovirus that provides the required early and late proteins necessary for replication.
Yet another viral vector system useful for delivery of nucleic acids is the adeno-associated virus (AAV). Adeno-associated virus is a naturally occurring defective virus that requires another virus, such as an adenovirus or a herpes virus, as a helper virus for efficient replication and a productive life cycle. (For a review see Muzyczka et al., Curr. Topics in Micro. And Immunol. 158:97-129 (1992). It is also one of the few viruses that may integrate its DNA into non-dividing cells, and exhibits a high frequency of stable integration (see for example Flotte et al., Am. J. Respir. Cell. Mol. Biol. 7:349-356 (1992); Samulski et al., J. Virol. 63:3822-3828 (1989); and McLaughlin et al., J. Virol. 62:1963-1973 (1989). Vectors containing as little as 300 base pairs of AAV can be packaged and can integrate. Space for exogenous DNA is limited to about 4.5 kb. An AAV vector such as that described in Tratschin et al., Mol. Cell. Biol. 5:3251-3260 (1985) can be used to introduce DNA into cells. A variety of nucleic acids have been introduced into different cell types using AAV vectors (see for example Hermonat et al., Proc. Natl. Acad. Sci. USA 81:6466-6470 (1984); Tratschin et al., Mol. Cell. Biol. 4:2072-2081 (1985); Wondisford et al., Mol. Endocrinol. 2:32-39 (1988); Tratschin et al., J. Virol. 51:611-619 (1984); and Flotte et al., J. Biol. Chem. 268:3781-3790 (1993). The identification of Staphylococcus aureus (SaCas9) and other smaller Cas9 enzymes that can be packaged into adeno-associated viral (AAV) vectors that are highly stable and effective, easily produced, approved by FDA, and tested in multiple clinical trials, paves new avenues for therapeutic gene editing. Of high relevance to GBM, better tissue distribution of AAV provides an additional advantage for invasive and recurrent tumors. Pla2g5-targeting AAV vectors of various serotypes, including AAV1, AAV2, AAV8, AAV9, and AAVrh.10, can be used, all of which were previously tested in clinical trials. Pla2g5 targeting AAV plasmid [based on Addgene Plasmids #61592, #61594], a single vector expressing SaCas9, gRNA, and Ampicillin selection marker can be utilized. Since PAM consensus sequence is different between SpCas9 and SaCas9 (the late cleaves genomic targets most efficiently with NNGRRT or NNGRR (R=A or G), as also the length required for SaCas9 gRNAs (21-23 nt), several targeting constructs have been designed.
Preferably, the CRISPR Pla2g5 editing complex is specific, i.e., induces genomic alterations preferentially at the target site (Pla2g5), and does not induce alterations at other sites, or only rarely induces alterations at other sites.
Administration
The present methods include delivery of the autologous Pla2g5-deficient suppressive macrophages into the airways of a subject. This can be achieved, e.g., using an aerosol spray of a suspension of cells into the nasal passage, or intratracheal (Urbanek et al., PloS One. 2016; 11(7): e0158746) or intrabracheal distilliation of a suspension of cells, e.g., via bronchoscopy (see Morales et al., BMC Pulmonary Medicine201515:66), or by intravenous delivery of the cells (since cells delivered IV pass through and may be entrapped therein, see Kean et al., Stem Cells International, Volume 2013 (2013), Article ID 732742, 13 pages). Preferably, the cells will be suspended in a physiologically acceptable media or buffer. In some embodiments, the cells are administered every 5 days, 7 days, every 10 days, e.g., when used as therapy for severe asthmatics, or every 2-3 weeks, or once a month. In some embodiments, the methods include administering 2, 3, of the 4 doses of the Pla2g5-deficient suppressive macrophages, and then no additional doses, or further doses as needed for flare-ups.
The cell compositions can be provided in a container, pack, or dispenser together with instructions for administration.
The invention is further described in the following examples, which do not limit the scope of the invention described in the claims.
Methods
The following materials and methods were used in the Examples below.
Lung Inflammation
C57/BL6 Wt and Pla2g5-null mice46, 47 (9-12 wk-old males) received 25 μg of Alternaria haracter extract (Greer Laboratories, Lenoir, N.C.) in 20 uL of PBS or PBS alone intranasally on days 0, 3, 6 and 9 and euthanized 18 hours later1 or a single dose of 100 μg and were euthanized after 1 h or 3 h2. For IL-33-induced pulmonary inflammation, Wt and Pla2g5-null naïve mice were given mouse rIL-33 (R&D Systems, Minneapolis, Minn.) intranasally (i.n.) 100 ng/dose on days 0, 3, 6 and 9 with or without LA (132 nM)28 or OA (106 nM), and mice were euthanized 18 hours after the last dose.
All animal experiments were approved by the Animal Care and Use Committee of the Dana-Farber Cancer Institute (Boston, Mass.).
Flow Cytometry
Lung were manually chopped to approximately 10 mm pieces, then digested in RPMI containing 428 U/ml Collagenase IV (Worthington, Lakewood, N.J.) and 20 mg/ml DNAse I (Roche, Mannheim, Germany) (30 min, 37° C.). After red cell lysis, the obtained cell suspension from single mouse was washed, and counted. After washing, cells were blocked (1 h, 4° C.) with 1% of rat anti mouse CD16/CD32 (BD Biosciences, San Jose, Calif.) and 10% donkey serum and then stained (1 h, 4° C.) with appropriate Abs. Mouse cells were stained with CD45 PercPCy5 (clone 30-F11, BioLegend, San Diego, Calif.), CD19 FITC (6D5, Biolegend), CD3 FITC (145-2C11, BioLegend), CD11b FITC (M1/70, BioLegend), CD11c PE-Cy7 FITC (N418, BioLegend), Ly6G/C FITC (RB6-8C5, eBiosciences), Nk1.1 FITC (PK136, Biolegend), FceR1 FITC (MAR-1, Biolegend), Siglec-F APC (E50-2440, BD Bioscience), Thy 1.2 APC (53-2.1, eBioscience, San Diego, Ca), ICOS (C398.4A, eBiosciences), Sca-1 (D7, eBioscieces), CD25 (PC61, eBiosciences), ST2 biotin (clone DJ8, MD Bioscience) followed by PE streptavidin (eBiosciences). In selected experiments cells were fixed with 4% paraformaldehyde (7 min, 21° C.), washed, permeabilized with 0.1% saponin (SigmaAldrich, St Louis, Ca) (7 min, 21° C.) and stained with CD68 APC (FA-11, AbD Serotec, Raleigh, Nc), IL-5 PE (TRFKS, Biolegend), IL-13 (eBio13A eBiosciences), IL-33 PE (396118, R&D Systems, Minneapolis, Minn.), rabbit polyclonal anti murine RELM-a (Peprotech, Rocky Hill N.J.)) and corresponding isotypes as controls. Acquisition was performed on a FACSCanto flow cytometer with FACSDiva software (BD Biosciences), and data were analyzed with FlowJo (Tree Star, Ashland, Oreg.).
Airways Analysis and Lung Cell Processing
Bronchoalveolar lavage (BAL) was performed with 0.7 mL PBS (Sigma-Aldrich) containing 0.5 mM EDTA (three times). The BAL fluid was collected, and cell-free supernatant was aliquoted and frozen. ELISA was used to measure IL-33 (R&D Systems).
Western Blot
Right lungs were collected at time of euthanasia and snap frozen. Proteins were isolated from tissue homogenates in RIPA buffer (Boston Bioproducts, Ashland, Mass., USA) with protease inhibitors26. The protein concentration in cell lysates was measured using the BCA Assay (Pierce, Thermo Scientific) and 20 μg of proteins were separated on a 10-20% Tris-Glycine gel (Novex, Life Technologies) and then transferred to a PVDF membrane. After blocking overnight at 4° C. in 5% milk, the blots were incubated with a goat polyclonal IL-33 (1:500, R&D Systems) or mouse monoclonal β-actin (1:1000, Cell Signaling, Danvers, Mass.) antibodies diluted in TBST at RT for 2h, followed by a rabbit anti-goat or goat anti-mouse secondary antibody (1:3000, BioRad) diluted in TBST for 1 hour at RT. The blots were visualized using the Supersignal West Femto Chemiluminescent substrate (Thermo Scientific) and imaged by a KODAK M35A X-OMAT processor.
Frozen Sections
Lungs of Wt and Pla2g5-null mice were excised and immersed in RPMI. Within 1h of surgery, the tissue was removed from RPMI and fixed in 4% paraformaldehyde, then embedded in Tissue-Tek® O.C.T.™ Compound (Sakura Finetek), and kept at −80° C. until sectioning. Sections of 5-μm thickness were freshly cut, thaw-mounted onto slides, and stained for confocal microscopy. Frozen sections were rehydrated for 1 hour at RT then blocked with 10% donkey serum, followed by incubation with goat polyclonal IL-33 (AF3626, R&D Systems) and rabbit polyclonal proSPC (AB3786, Millipore, Temecula, Calif.) antibodies or appropriate isotypes controls at 4° C., overnight. Samples were washed and incubated at RT for 1 hour with appropriate secondary antibodies. The sections were washed and covered with Fluoroshield mounting media (Electron Microscopy Sciences, Hatfield, Pa.). Sections were imaged using a Nikon Cl plus laser scanner confocal system with a 40× oil Plan-Fluor NA1.3 objective lens. 8-10 Z-stack images of 0.5 μm were acquired through a small pinhole using Nikon EZ-C1 software. Images were analyzed using Image J (U.S. National Institute of Health, Bethesda, Md.).
BM Macrophage Transfer
Wt bone marrow (BM) cells were collected from femurs and tibiae of mice. The disaggregated cells were counted and suspended in complete medium (DMEM F12, 5% FBS, 100U/ml penicillin, 100 ug/ml streptomycin, 0.1 mM nonessential amino acids, 2 mM L-glutamine and 0.05 μM 2-ME) containing 50 ng/ml murine r-MCSF (PeproTech) at a concentration of 4.0×106 cells/ml in a 10 ml/Petri dish. On day 3, 10 ml of medium containing r-MCSF were added to each dish. On day 7, cells were harvested with PBS containing Lidocaine (4 mg/ml, 15 min, 37 C) and resuspended at concentration of 5×106 cells/ml in PBS. For adoptive transfer, 1×105 BM-macrophages were transferred i.t. into Wt and Pla2g5-null mice two days after the first dose of Alternaria followed by 3 more doses of Alternaria (25 μg in 20 μl PBS) intranasally (i.n.) on day 3, 6 and 9. Mice were euthanized 18h after last dose.
Mass Spectrometry of Lipids
Wt and Pla2g5-null BM-macrophages were cultured for 7 days in r-MCSF. Adherent cells were collected, frozen and shipped for analysis by mass spectrometry. Free fatty acid analysis was performed according to a previously published method32, 48. Briefly, the cell pellet was homogenized in 500 ul of PBS/10% methanol. An aliquot of 200 μl corresponding to about 0.5×106 cells was withdrawn and a cocktail of internal standards consisting of 15 deuterated fatty acids was added. The extraction was initiated with 500 μl of methanol and 25 μl of 1N HCl and a bi-phasic solution is formed by addition of 1.5 ml of isooctane. The phases are separated by centrifugation and the isooctane phase containing the free fatty acids FFA fraction was removed. The extraction is repeated once and the combined extracts are evaporated to dryness. The free fatty acids were derivatized with pentafluorobenzyl (PFB) bromide and the resulting fatty acid PFB esters were analyzed by gas chromatography/mass spectrometry using a negative chemical ionization mode (Agilent 6890N gas chromatograph equipped with an Agilent 5973 mass selective detector; Agilent, Santa Clara, Calif.). Standard curves for each of the fatty acids were acquired in parallel using identical conditions. The quantitative assessment of fatty acids in a sample was achieved by comparison of the mass spectrometric ion signal of the target molecule normalized to the internal standard with the matching standard curve according to the isotope dilution method and by protein content32.
ILC2 Cells Sorting and Culture
Wt and Pla2g5-null mice received four doses of 25 ug of Alternaria in 20 ul of PBS intranasally on day 0, 3, 6 and 9 and euthanized 18h later in order to expand ILC2 prior to FACs sorting. Sorting of ILC2 (CD45+ Lin− (CD3, CD19, Ly6g, CD11c, CD11b, Nk1.1, FcεR1−), Thy1.2+) was performed using a FACSDiva 8.0.1 cell sorter (BD bio-science). Purified ILC2 (>98%) were rested for 40 hours with 10 ng/mL rIL-2 and rIL-7 (R&D Systems, Minneapolis, Minn.) in a 96 well around bottom plates (20000 cells per well). Prior to stimulation, the medium was changed to fresh medium. ILC2 were cultured with 30 ng/mL rIL-33 (R&D Systems), 200 μM Linoleic Acid (Cayman Chemical) or 200 μM Oleic Acid (Cayman Chemical)22 or all together for 8h. For intracellular cytokine staining, 1 μl/mL of Golgi Plug (BD Bioscience) was added to ILC2 6h before collection for FACs analysis.
Real-Time PCR
Total RNA was isolated from lysate with the Rneasy Micro Kit (Qiagen, Louisville, Ky., USA), reverse transcribed into cDNA (High-Capacity cDNA Reverse Transcription Kit; Thermo Science-Applied Biosystems, Foster City, Calif., USA) and measured by real-time PCR for FFAR1 and Pla2g5 with the use of SYBR Green/ROX master mix (SABiosciences, Frederick, Md., USA) on an Mx3005P thermal cycler (Stratagene, Santa Clara, Calif., USA). The ratio of each mRNA relative to the GAPDH mRNA was calculated with the ΔΔCt threshold cycle method. The mouse primers used were GAPDH F: TCAACAGCAACTCCCACTCTTCCA (SEQ ID NO:1); R: ACCCTGTTGCTGTAGCCGTATTCA (SEQ ID NO:2). Pla2g5 F: TGGTTCCTGGCTTGCAGTGTG (SEQ ID NO:3); R: TTCGCAGATGACTAGGCCATT (SEQ ID NO:4). FFAR1/GPR40 and FFAR4/GPR120 were from Qiagen.
Real-time PCR products were run on a 1.5% agarose gel and visualized using chemilmager 4400 fluorscience system (Alpha Innotech, Missouri, TEX, USA).
Human Monocyte-Derived Mϕ
Leukocyte-enriched buffy coat from healthy donors was overlaid on Ficoll-Paque Plus (GE Healthcare, Buckinghamshire, UK) and centrifuged at 600 g for 20 min. The mononuclear layer at the interface was collected, washed, and counted. Monocytes were isolated by negative selection (Miltenyi Biotec, Auburn, Calif.) and plated at 1-1.5×106 cells/ml in 30-mm Petri dishes, or 2.2×105 cells/cm2 in 100-mm Petri dishes (Ohta et al., J Immunol 190, 5927-5938). To derive macrophages, monocytes were cultured for 13 days in complete medium (RPMI 1640, 10% FBS, 2 mM L-glutamine, 100U/ml penicillin, 100 μg/ml streptavidin, 10% non-essential amino acids, 1% HEPES, 1% sodium pyruvate, 50 μM 2-ME) supplemented with 50 ng/ml human rGM-CSF (R&D Systems, Minneapolis, Minn.) (Martinez et al. Blood 121, e57-69; Beyer et al., PloS One 7, e45466). To activate macrophages, cells were polarized for 6, 18, 24, or 48 hours in complete medium, supplemented with 40 ng/ml human IL-4 (R&D Systems). To knock down PLA2G5, after culturing the monocytes for 13 days in recombinant GM-CSF, cells were transfected with human PLA2G5 ON-TARGET Plus SMART Pool siRNA or non-targeting vector ON-TARGET Plus Control Pool (1000 nM; GE Dharmacon, Lafayette, Colo.) using the Amaxa Human Macrophage Nucleofector kit (Amaxa, Lonza, Germany), according to the manufacturer's instructions. After 24 h, the transfection medium was replaced by complete medium. Twenty-four hours later, cells were polarized with IL-4 for 6, 18, 24 or 48h. In selected experiments PGE2 or human recombinant PLA2G5 (Cayman, Ann Arbor, Mich.) was added to cells (Ishitanit et al., J Biochem 104, 397-402).
Statistical Analysis
Comparisons between 2 groups were made by using unpaired Student's t test. To compare three or more groups, we performed One-way ANOVA with Sidak's correction for multiple comparisons. Comparisons were performed with Prism software (GraphPad, La Jolla, Calif.). Data are expressed as mean±SEM, and P<0.05 was considered significant.
To investigate the role of Pla2g5 in activation of ILC2, we used a model of allergic pulmonary inflammation induced by Alternaria, which relies on ILC2 activation to cause eosinophilic inflammation. We administered Alternaria (25 μg/dose) every two days for four doses and lungs were collected 18h after the last dose1. Wt mice treated with Alternaria had significantly increased total lung cell numbers compared to Alternaria-treated Pla2g5-null mice (
Whereas IL-33 is constitutively expressed by lung barrier cells, its expression can also be upregulated during sustained inflammatory responses, in part reflecting the contributions from hematopoietic cells30. To investigate whether the reduced ILC2 activation in Pla2g5-null mice was due to lack of either constitutive or inducible pools of IL-33, we measured IL-33 release into the BAL fluids of I mice after administration of a single Alternaria dose. We also monitored the content of IL-33 in the lung at baseline and after 4 doses of Alternaria using western blotting. We found that I Wt and Pla2g5-null mice released similar amounts of IL-33 into BAL at 1 and 3 hours after Alternaria challenge (
To identify the cellular source(s) responsible for the constitutive and inducible pools of IL-33, we stained frozen sections of Wt and Pla2g5-null mice with anti-IL-33. Since alveolar type 2 pneumocytes (AT2) are one of the major sources of IL-33 in Alternaria challenged mice15, we counterstained the lung sections with Abs against the AT2 cell marker surfactant protein C (SPC). Lungs of both Wt and Pla2g5-null mice showed IL-33 in the nuclei of SPC+AT2 cells at baseline, and there was no difference between Wt and Pla2g5-null Alternaria challenged mice (
Next, we wanted to ascertain whether exogenous recombinant I-IL-33 would restore eosinophilia and ILC2 activation in Pla2g5-null mice. Administration of IL-33 over 10 days (
Because macrophages require endogenous Pla2g5 for their functions in pulmonary inflammation25, we wanted to investigate whether ILC2 activation and downstream lung inflammation could be restored to Pla2g5-null mice by reconstituting Pla2g5 function in macrophages. We adoptively transferred unstimulated Wt BM-macrophages into Wt and Pla2g5-null recipient mice 24h before the second dose of Alternaria, then administered 3 more doses and analyzed eosinophils numbers and ILC2 activation (
To identify candidate Pla2g5-derived mediators generated by macrophages that could contribute to ILC2 activation, we performed an unbiased assessment of lipids constitutively released by Wt and Pla2g5-null BM-macrophages, using mass spectrometry32. Compared to Wt BM-macrophages, Pla2g5-null BM-macrophages produced significantly lower quantities of medium- and long-chain FFAs, mostly represented by oleic acid (OA, 18:1), LA (18:2), and AA (20:4) (
To determine whether LA and/or OA could restore the IL-33-mediated induction of eosinophilic inflammation and ILC2 expansion, we administered intranasal LA and/or OA, alone and in combination with IL-33 (4 doses in 10 days), to Wt and Pla2g5-null mice. Neither LA nor OA alone caused pulmonary inflammation in either genotype (
To determine whether LA and/or OA directly activated ILC2s, we sorted ILC2s from lungs of Alternaria-treated Wt and Pla2g5 null mice, rested them for 40 h, and stimulated with LA, OA, IL-33 or a combination for 8 h. Then we assayed ILC2s for their expression of intracellular IL-5. IL-33 significantly increased the percentage of IL-5-expressing ILC2s isolated from both Pla2g5-null and Wt mouse lungs. Neither LA nor OA induced significant IL-5 expression by ILC2s of either genotype. LA, but not OA, significantly potentiated IL-33-induced expression of IL-5 by Wt ILC2s, and the combination of LA+OA did not differ from the effects of LA (
Medium-long chain FFAs signal through two G protein-coupled receptors, FFA receptor-1 (FFAR1) and FFA receptor-4 (FFAR4)33-37. To determine whether ILC2s expressed these receptors, and to determine the potential basis for the different responses of Wt and Pla2g5-null ILC2s to LA, we analyzed ILC2 expression of FFAR1 and FFAR4 in ILC2 sorted from Wt and Pla2g5-null Alternaria-treated mice. Wt ILC2s expressed FFAR1 mRNA and its expression was significantly higher compared to Pla2g5-null ILC2s (
Methods:
For adoptive transfer, 1×105 Wt or Pla2g5-null BM-Macs activated with a cocktail of Th2 cytokines I and generated as follows. WT and Pla2g5-null bone marrow (BM) cells were collected from femurs and tibiae of mice. The disaggregated cells were counted and suspended in complete medium containing 50 ng/ml murine r-M-CSF (PeproTech) at a concentration of 4.0×105 cells/ml, 10 ml/Petri dish. On day 3, 10 ml of medium containing r-M-CSF were added. On day 7, the cells were pulsed with 20 ng/ml of IL-4 (PeproTech), IL-33 (R&D) and GM-CSF (PeproTech) (cocktail, C) or nothing. After 24 h, cells were harvested with PBS containing Lidocaine (4 mg/ml) and EDTA (5 mM) (15 min, 37° C.) (39). For adoptive transfer, 1×105 WT and Pla2g5-null BM-macrophages (described in Ohta J I 2013), were transferred i.t. into Wt mice two days after the first dose of Alternaria haracter followed by 3 more doses of Alternaria (25 ug in 20 ul PBS) intranasally (i.n.) on day 3, 6 and 9. Mice were euthanized 18h after last dose (as in
Results: This set of experiments (
Conclusions: These data suggest that the transfer of macrophages lacking Pla2g5 into “asthmatic” Wt mice reduces critical features of pulmonary inflammation/asthma.
It is to be understood that while the invention has been described in conjunction with the detailed description thereof, the foregoing description is intended to illustrate and not limit the scope of the invention, which is defined by the scope of the appended claims. Other aspects, advantages, and modifications are within the scope of the following claims.
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